The unit graph of a left Artinian ring

Let R be a ring with non-zero identity and U(R) be the group of units of R. The unit graph of R, denoted by G(R), is a graph defined on the elements of R, and two distinct vertices r and s are adjacent if and only if r+s∈U(R). We investigate connectivity, diameter and the girth of the unit graph of a left Artinian ring. Also, by providing an algorithm, we determine when the unit graph of a finite ring is Hamiltonian.     

Poly(Butylene Terephthalate)/Single Wall Carbon Nanotubes Composite Nanofibers by Electrospinning

Poly(buthylene terephthalate)(PBT)/single wall carbon nanotubes (SWCNTs) composite nanofibers were prepared by electrospinning. The effect of carbon nanotubes on the morphology, crystallization, and mechanical properties of the electrospun composite nanofibers were investigated by SEM, DSC, and tensile testing, respectively. SEM observations indicated that the presence of SWCNTs resulted in finer nanofibers for lower loading; however, a broader distribution, especially for the higher diameter ranges was found for nanofibers with higher amounts of carbon nanotubes. SWCNTs accelerated crystallization and acted as a nucleating agent; the degree of crystallinity increased with increasing content of SWCNTs, followed by a moderate decrease at higher content. Specific tensile strength and modulus of the PBT/SWCNTs composite nanofibers mats were higher than that of neat PBT nanofibers mat. However, the elongation at break of composite nanofibers mats was lower than that of the neat PBT nanofibers mat.     

Silver nanoparticles with gelatin nanoshells: photochemical facile green synthesis and their antimicrobial activity

In the current study, a facile green synthesis of silver-gelatin core–shell nanostructures (spherical, spherical/cubic hybrid, and cubic, DLS diameter: 4.1–6.9 nm) is reported via the wet chemical synthesis procedure. Sunlight-UV as an available reducing agent cause mild reduction of silver ions into the silver nanoparticles (Ag-NPs). Gelatin protein, as an effective capping/shaping agent, was used in the reaction to self-assemble silver nanostructures. The formation of silver nanostructures and their self-assembly pattern was confirmed by SEM, AFM, and TEM techniques. Further investigations were carried out using zeta-potential, UV–Vis, FTIR, GPC, and TGA/DTG/DTA data. The prepared Ag-NPs showed proper and acceptable antimicrobial activity against three classes of microorganisms (Escherichia coli Gram-negative bacteria, Staphylococcus aureus Gram-positive bacteria, and Candida albicans fungus). The antibacterial and antifungal Ag-NPs exhibit good stability in solution and can be considered as promising candidates for a wide range of biomedical applications.     

A magnetically recoverable copper–salen complex as a nano-catalytic system for amine protection via acetylation using thioacetic acid

Research on Chemical Intermediates - A novel copper(II)–salen complex was immobilized on the surface of magnetite nanoparticles using chitosan as a linker. This system exhibits superior...     

Convergence analysis of an iterative algorithm to solve system of nonlinear stochastic Itô-Volterra integral equations

In this paper, an efficient and accurate numerical iterative algorithm based on the linear spline interpolation for solving the system of nonlinear stochastic Itô-Volterra integral equations is presented. The most important merit of this method is that it does not need to solve any system of nonlinear algebraic equations. An upper bound for the linear spline approximation of the stochastic function is provided. Using this upper bound and under the Lipschitz and linear growth conditions, the convergence analysis of the suggested method is studied. Finally, to verify the efficiency of the proposed scheme, some problems in the finance, physics, and biology are investigated, and the obtained results are compared with the stochastic $\theta$-method.     

Copper(I)–creatine complex on magnetic nanoparticles as a green catalyst for N- and O-arylation in deep eutectic solvent

Immobilization of copper(I) ions on magnetic nanoparticles was performed using surface modification of Fe₃O₄ with creatine. Fe₃O₄@creatine-Cu(I) magnetic catalyst was synthesized and applied in C&bond;X cross-coupling reactions with aryl halides in a deep eutectic as a green solvent. The results indicate the Fe₃O₄@creatine-Cu(I) magnetic nanoparticles showed excellent activity and high stability. In addition, it was revealed that this catalyst can be recycled five times without significant loss in catalytic activity.     

Nanomagnetically modified sulfuric acid (γ-Fe2O3@SiO2-OSO3H): an efficient, fast, and reusable green catalyst for the Ugi-like Groebke-Blackburn-Bienaymé three-component reaction under solvent-free conditions

Superparamagnetic nanoparticles of modified sulfuric acid (γ-Fe₂O₃@SiO₂-OSO₃H) represent a straightforward and green catalyst for the rapid synthesis of aminoimidazopyridine skeletons via the Ugi-like Groebke-Blackburn-Bienaymé three-component reaction. The γ-Fe₂O₃@SiO₂-OSO₃H catalyst could be recovered and reused in five reaction cycles, giving a total TON = 453. The products were prepared under solvent-free conditions without any additives.     

Double step buried oxide (DSBO) SOI-MOSFET: A proposed structure for improving self-heating effects

For the first time, a novel structure named as double step buried oxide silicon-on-insulator-MOSFET (DSBO-SOI) is proposed, which can combine the advantages of both SOI structure and bulk structure. Design consideration for a 30 nm channel length SOI-MOSFET employing double step buried oxide (DSBO) is presented. The electrical characteristics and temperature distribution are analyzed and compared with ultra-thin body silicon-on-insulator (UTB-SOI) MOSFET. The DSBO devices are shown to have better leakage and sub-threshold characteristics. Furthermore, the channel temperature is reduced during high-temperature operation and drain current increase suggesting that DSBO can mitigate the self-heating penalty effectively. Our results suggest that DSBO is an alternative to silicon dioxide as the buried dielectric in SOI, and expands the application of SOI to high temperature.