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The Langmuir rate equation, a linear combination of the pseudo-first-order and pseudo-second-order kinetics models, is expressed as d θ d t = k 1 (θ e − θ) + k 2 (θ e − θ) 2. This study introduces a novel theoretical approach to evaluate the percent contribution of these kinetics models in constructing the Langmuir rate equation for 18 selected adsorption systems. The proposed approach accurately calculates the contribution of the pseudo-first-order and pseudo-second-order kinetics models, providing valuable insights into their relative significance in the adsorption process. The findings offer important implications for understanding and modeling adsorption kinetics in diverse systems. • Introducing a novel method for quantifying the contribution of PFO and PSO models in the Langmuir rate equation. • Determining the contribution of PFO and PSO models in the Langmuir rate equation for 18 adsorption systems. • Validating the high accuracy of the integrated Langmuir rate equation in calculating the equilibrium adsorption capacity. [ABSTRACT FROM AUTHOR]

Highlights • Copper/ reduced single layer graphene oxide (Cu/ rSLGO) was developed by a simultaneous in-situ reduction of Cu+2 ions and SLGO nanosheets. • The SP2 hybridization of rSLGO nanosheets and the conductive connections between them by Cu nanoparticles lead to good antistatic properties. Abstract Development of a surface with simultaneous antibacterial and antistatic properties is necessary for some special environments like operating rooms and high-tech industries. Multifunctional copper/ reduced single layer graphene oxide (Cu/ rSLGO) nanohybrid has been developed to induce these simultaneous properties in waterborne polyurethane coatings (WPU). The Cu/ rSLGO nanohybrid was synthesized through the in-situ reduction of Cu+2 ions and single layer graphene oxide nanosheets without using any secondary reducing reagent. FESEM, TEM, FTIR, XRD, EDX, UV–vis, and TGA analyses were used to characterize morphological, structural, crystallographic, and thermal properties of the prepared nanohybrid, and the modified WPU coatings were studied by SEM, AFM, contact angle, TGA, DLS, and mechanical properties analyses. The results of the colony counting method exhibited that the Cu/ rSLGO nanohybrid has a strong antibacterial activity with 92% and 80.66% of the loss of viability for S. aureus and E. coli bacteria, respectively. Moreover, adding 3%wt Cu/ rSLGO nanohybrid and the creation of sufficient conductive pathways throughout the WPU matrix lead to the electrical surface resistance of the modified coating reaches 4.8 × 10+9 Ω/sq which falls into the electrical surface resistance range of commercial antistatic coatings. Furthermore, utilizing the Cu/ rSLGO in the WPU coating not only provided thermal resistance but also, enhanced its mechanical properties compared with the coating made of pristine waterborne polyurethane. [ABSTRACT FROM AUTHOR]

Determination of heavy metals at trace levels has a great deal of importance due to their undesirable effects on human life. In this study, N,N′-bis (acetyl acetone) ethylenediimine (Fe 3 O 4 @SiO 2 -EDN) was synthesized and applied for dispersive solid phase extraction of copper in water and cereal samples followed by FAAS. Sorbent characterization was investigated by SEM, FT-IR, EDX and VSM. The effective parameters were optimized using a central composite design. Under the optimal conditions, LOD (S/N = 3) and LOQ, preconcentration factor and RSD% were found to be 1.5 ng mL −1 , 4.0 ng mL −1 , 13 and 2.3%, respectively. The calibration curve was linear within the range of 4.0–175 ng mL −1 with r 2  > 0.998. Relative recoveries were achieved within the range of 90.0–95.0%. With thanks of the good resulting analytical performance in this work, the proposed method can be applied as a suitable alternative for trace analysis of copper. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study is to measure the Compton profile of a titanium coating on a glass substrate, comparing it with a profile computed by the Hillman and Skilman program based on the Hartree–Fock model. The experimental Compton profile was obtained using 661.7keV gamma-rays from a 1Ci 137Cs source and a 3″×3″ NaI(Tl) detector. The experimental, theoretical and unfolded Compton profiles of titanium have been compared. The results illustrate the breadth of experimental Compton profile in comparison with the two others. This difference can be mainly attributed to the Doppler broadening effect, the final quantum state of the electron and partly by the approximations implemented in the theoretical model. [Copyright &y& Elsevier]

• Piriformospora indica colonization increases physiological parameters to enhance adapt to stress. • Piriformospora indica colonization adjusts gene expression in the host plant to reduce negative effect imposed by drought stress. • Piriformospora indica colonization helps the tomato plants to tolerate the drought stress. Endophytic fungi can colonize several plant species and, in that way significantly alleviate the adverse effects of environmental stresses. Endophytic fungus of the order Sebacinales, Piriformospora indica, can be cultivated axenically and colonizes the root of a wide range of plants, not only promotes the growth, but also increases the plant tolerance to abiotic stress. The present study evaluated the effect of the inoculation of two tomato cultivars (Superluna and Caspian) with P. indica to ameliorate the effect of drought stress by analyzing plant growth, and some morpho-physiological parameters. Also, the expression and promotor analysis of LEA14, TAS14, GAI, and P5CS genes was investigated. Results showed that drought stress decreases shoot fresh and dry weight, relative water content and proline level. The tolerant cultivar (Caspian) had a higher level of Shoot weight, RWC and proline compared to the sensitive cultivar (Superluna). Likewise, P. indica colonization increased the measured factors in both tomato cultivars under normal and drought stress conditions. Also, gene expression analysis showed that except for the GAI gene, the expression of other genes was increased in drought and fungus treatments, and the interaction effect of the two treatments increased the expression of these genes. The results suggested that the symbiotic association between plant and fungus could help the tomato plants to tolerate the drought stress through physiological and molecular pathways, opening up a window of opportunity for its application in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Abstract: The present work develops two numerical models to compute thermal phenomena during pulsed laser welding. The first one which is based on finite difference model calculates the welding width and its penetration by utilizing heat transfer equations. Parametric design capabilities of the finite element code ANSYS were also employed for the simulation of the second model. The transient temperature profiles, the fusion dimensions and the heat affected zones (HAZ) have been calculated here. The thermo-physical properties are dependent on temperature and so a nonlinear solution is employed. It is found that the temperature profile and penetration depth are strongly dependent on the pulse parameters of laser beam. Finally, the results of the two models and the experimental outcomes are compared. [Copyright &y& Elsevier]

Abstract: Among many conventional techniques, nuclear techniques have shown to be faster, more reliable, and more effective in detecting explosives. In the present work, neutrons from a 5Ci Am–Be neutron source being in water tank are captured by elements of soil and landmine (TNT), namely 14N, H, C, and O. The prompt capture gamma-ray spectrum taken by a NaI (Tl) scintillation detector indicates the characteristic photo peaks of the elements in soil and landmine. In the high-energy region of the gamma-ray spectrum, besides 10.829MeV of 15N, single escape (SE) and double escape (DE) peaks are unmistakable photo peaks, which make the detection of concealed explosive possible. The soil has the property of moderating neutrons as well as diffusing the thermal neutron flux. Among many elements in soil, silicon is more abundant and 29Si emits 10.607MeV prompt capture gamma-ray, which makes 10.829MeV detection difficult. The Monte Carlo simulation was used to adjust source–target–detector distances and soil moisture content to yield the best result. Therefore, we applied MCNP4C for configuration very close to reality of a hidden landmine in soil. [Copyright &y& Elsevier]

• Polyaniline/cationic reduced graphene oxide (P-RGO+) nanohybrids were developed by the in-situ interfacial polymerization method. • The good exfoliation of RGO+ nanosheets and the passive layer of PANI nanofibers can prevent the diffusion of corrosive agents to the metal surface. • The SP2 hybridization of RGO+ nanosheets and the conductive connections between them by PANI nanofibers lead to a good antistatic property. • Antibacterial activity of the nanohybrid is justified by the positive charge of PANI and the physical damages occurred by RGO+ nanosheets. Development of a coating with simultaneous anticorrosion, antistatic, and antibacterial properties is an important issue which has gained attention from both academic and industrial societies. Multifunctional Polyaniline /cationic reduced graphene oxide (P-RGO+) nanohybrid has been synthesized to induce these properties in waterborne polyurethane (WPU) coatings. The cationic reduced graphene oxide nanosheets (RGO+) were obtained through the in-situ reduction and functionalization with Dimethylformamide (DMF). The cationic reduced graphene oxide nanosheets were intercalated with Polyaniline nanofibers (PANI) to prepare a binary nanohybrid (P-RGO+). This nanohybrid was characterized through the FTIR, XRD, FESEM, and zeta potential techniques and its effect on anticorrosion, antistatic, antibacterial, and mechanical properties of the waterborne polyurethane coatings was studied. The results of Tafel and EIS plots exhibited that the modified coatings have an improved performance in term of protecting steel substrates against corrosion. Moreover, in the presence of the nanohybrid, the electrical surface resistance of the obtained coating reduced to reach 9.8 × 10+6 Ω/sq so that it can be counted as an antistatic coating. Moreover, utilizing P-RGO+ nanohybrid in the WPU dispersion not only improved antibacterial activity against both gram positive and gram negative bacteria but also caused the enhanced mechanical properties of the modified coating compared with the pristine coating. [ABSTRACT FROM AUTHOR]

The Langmuir adsorption rate equation was obtained in its exact, linear, and simple form. Using Stochastic Numerical Simulation, it was demonstrated that this equation can accurately calculate the adsorption rate constant (k a), which is more precise than the values obtained using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. The derivation conditions of the PFO and PSO kinetics models from Langmuir kinetics were also investigated. The results showed that the PFO model can be obtained at two limit states: at C e ≅ C 0 and at C e ≪ C 0 with a very low fractional coverage. Also, the PSO model is derived under the condition C e → 0 and θ e → 1. The accuracy of the exact Langmuir model, both linear and nonlinear, and the theoretical derivation conditions of the PFO and PSO models were examined using several sets of kinetics data generated by the Stochastic Numerical Simulation method. The simulation results supported the theoretical approaches of this study. • Obtaining the exact solution of the Langmuir kinetics (EIL). • Deriving the Pseudo-First-Order model under the condition of C e ≅ C 0. • Deriving the Pseudo-First-Order model at short initial times of adsorption under C e ≪ C 0 condition. • Deriving the Pseudo-Second-Order model under the condition of C e → 0 and θ e → 1. • Evaluating the derivation conditions of PFO and PSO models using the Stochastic Numerical Simulation method. [ABSTRACT FROM AUTHOR]

Carbon nitride two-dimensional (2D) materials are among the most attractive class of nanomaterials, with wide range of application prospects. As a continuous progress, most recently, two novel carbon nitride 2D lattices of C 3 N 5 and C 3 N 4 have been successfully experimentally realized. Motivated by these latest accomplishments and also by taking into account the well-known C 3 N 4 triazine-based graphitic carbon nitride structures, we predicted two novel C 3 N 6 and C 3 N 4 counterparts. We then conducted extensive density functional theory simulations to explore the thermal stability, mechanical, electronic and optical properties of these novel nanoporous carbon-nitride nanosheets. According to our results all studied nanosheets are found to exhibit desirable thermal stability and mechanical properties. Non-equilibrium molecular dynamics simulations on the basis of machine learning interatomic potentials predict ultralow thermal conductivities for these novel nanosheets. Electronic structure analyses confirm direct band gap semiconducting electronic character and optical calculations reveal the ability of these novel 2D systems to adsorb visible range of light. Extensive first-principles based results by this study provide a comprehensive vision on the stability, mechanical, electronic and optical responses of C 3 N 4 , C 3 N 5 and C 3 N 6 as novel 2D semiconductors and suggest them as promising candidates for the design of advanced nanoelectronics and energy storage/conversion systems. Image 1 [ABSTRACT FROM AUTHOR]

• The stability of H-, F- and Cl-diamanes 2D lattices is examined. • Mechanical and electronic properties of H-, F- and Cl-diamanes are studied. • Effects of number of carbon atomic layers on the intrinsic properties are explored. Most recently, fluorinated diamond monolayer so called "F-diamane" has been successfully experimentally realized via fluorination of bilayer-graphene (Nat. Nanotechnol. 15 (2020), 59–66). Motivated by this experimental advance, we conduct density functional theory simulations to explore the stability, mechanical, electronic and optical properties of diamane nanosheets. In this work we consider diamane nanosheets functionalized with H, F and Cl atoms. We particularly examine thickness effect on the properties of functionalized diamane nanomembranes. According to phonon dispersions and ab-initio molecular dynamics results, thermal and dynamical stability of studied systems are confirmed. It is found that by increasing the number of carbon layers in diamane the elastic modulus and tensile strength increase. Analysis of electronic band-structures reveal that while H- and F-diamane are wide band gap semiconductors and insulators, respectively, Cl-diamanes are direct band gap semiconductors, highly promising for nanoelectronics applications. Optical calculations show that Cl-diamane can absorb the visible light whereas H and F counterparts absorb ultraviolet range of light. First-principle results by this study provide a comprehensive vision on the thickness dependent mechanical, electronic and optical responses of functionalized diamane nanosheets and can serve as a useful guide for future studies. [ABSTRACT FROM AUTHOR]