Porous triazine polymer: A novel catalyst for the three-component reaction

A new porous triazine-based covalent organic polymer (Triazine-COP) was prepared through the Schiff-base condensation of 2,4,6-tris(4-formyl phenoxy)-1,3,5-triazine and 4,4′-oxydianiline, under sonication. The synthesized Triazine-COP with a high surface area was stable in water and other organic solvents. In the next step, Au (III) ions were immobilized on the nitrogen-rich Triazine-COP that on the reduction with NaBH₄ produced the heterogeneous catalyst of gold clusters in nanosize (Au-NCs@Triazine-COPs). It was applied as an efficient catalyst for the A³ coupling reaction of alkynes, aldehydes with and amines. Both electron-withdrawing/releasing groups produced the corresponding propargylamines with high yields. The high activity of the Au-NCs@Triazine-COPs in this reaction was because of the nanoporous structure of the support that enables the high dispersion and an unhindered open environment for the NCs. The catalyst was reused up to 7 times without significant loss in activity.     

A new quality appearance evaluation technique for automotive bodies including effect of flexible parts tolerances

Part tolerances have a crucial effect on the quality of products. In vehicle design, tolerance analysis is of central importance in quality appearance evaluation of automotive bodies and significantly taken into consideration by manufacturers in recent decades. This paper evaluates the surface quality of a car’s roof as one of the key quality characteristics in vehicle design. Compared to previous research in the area of quality appearance evaluation of automotive bodies, which are based on the assumption of part rigidity, the current research proposes to include part flexibilities in the analysis. The results of this study shows that input tolerances have a considerable effect on the surface quality of the final assembled product.     

Simulation of Structure Change in Porous Media During Gas–Solid Reactions Using Cellular Automata Model

Transport in Porous Media - In some gas–solid reactions, a new solid substance is produced. The product acts as a shield and prevents the collision between gas and solid reactants which...     

Ziziphora clinopodioides Lam leaves aqueous extract mediated synthesis of zinc nanoparticles and their antibacterial,antifungal, cytotoxicity,antioxidant, and cutaneous wound healing properties under in vitro and in vivo conditions

LamZiziphora clinopodioides Biosynthesis of metal nanoparticles using plant medicine is under exploration is due to wide biomedica applications and research interest in nanotechnology, the recent study was assessing green synthesis of zinc nanoparticle using ), the use of plant material Ziziphoraleaves extract (ZnNPs@ not only makes the process eco‐friendly but also the abundance makes it more economical. Also, in this study, Vis. and– were characterized using different techniques including UVZiziphora were synthesized in aqueous medium using the plant extract as stabilizing and reducing agents. The synthesized ZnNPs@Ziziphora conditions. ZnNPs@in vivo and in vitro under Ziziphorawe investigated the therapeutical properties of ZnNPs@ FT‐IR spectroscopy, . SEM images exhibited a uniform spherical morphology in size of 32.34 Thermal Gravimetric Analysis (TGA)ray diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersive X‐ray Spectrometry (EDS), and‐X Escherichia coli, and Pseudomonas aeruginosa, Salmonella typhimurium part of this study, these nanoparticles indicated excellent antibacterial properties against Gram‐negative bacteria (in vitronm for the biosynthesized nanoparticles. In the biological , andCandida krusei, Candida albicans, Candida glabrata), antifungal potentials against Bacillus subtilis, andStaphylococcus aureus, Streptococcus pneumoniaO157:H7) and Gram‐positive bacteria ( leaves aqueous extract can be used to yield zinc nanoparticles with a significant amount of antibacterial, antifungal, antioxidant, and cutaneous wound healing properties without any cytotoxicity.Z. clinopodioides ointment ameliorated the cutaneous wounds with increasing the levels of wound contracture, vessel, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate and decreeing the wound area, total cells, and lymphocyte compared to other groups in rats. The results of UV, FT‐IR, XRD, FE‐SEM, EDS, and TGA confirm that the Ziziphora part of our experiment, ZnNPs@in vivo, non‐cytotoxicity effect against human umbilical vein endothelial cells, and antioxidant activity against DPPH. In the biological Candida guilliermondii     

Fischer-Tropsch synthesis over ruthenium-promoted Co/Al2O3 catalyst with different reduction procedures

The effect of reduction procedure on catalyst properties, activity and products selectivity of ruthenium-promoted Co/γ-Al2O3 catalyst in Fischer-Tropsch synthesis (FTS) was investigated. Catalyst samples were reduced with different reduction gas compositions and passivated before being characterized by TPR and XRD techniques. Different activity and product selectivity analyses were also performed. These results showed that the catalyst dispersion, particle size, and the degree of reduction changed with different reduction gas compositions, which were resulted from the water partial pressures in reduction process that give varying degrees of interaction with the support. It has been suggested that the FTS activity of cobalt catalyst was directly dependent on the catalyst reducibility. A reduction gas with a molar ratio of H2/He = 1 was used to prevent the formation of Co-support compound during catalyst reduction.     

Coarse homotopy groups

In this note on coarse geometry we revisit coarse homotopy. We prove that coarse homotopy indeed is an equivalence relation, and this in the most general context of abstract coarse structures. We introduce (in a geometric way) coarse homotopy groups. The main result is that the coarse homotopy groups of a cone over a compact simplicial complex coincide with the usual homotopy groups of the underlying compact simplicial complex. To prove this we develop geometric triangulation techniques for cones which we expect to be of relevance also in different contexts.     

Thermal fluctuations in a hyperscaling-violation background

In this paper, we study the effect of thermal fluctuations on the thermodynamics of a black geometry with hyperscaling violation. These thermal fluctuations in the thermodynamics of this system are produced from quantum corrections of geometry describing this system. We discuss the stability of this system using specific heat and the entire Hessian matrix of the free energy. We will analyze the effects of thermal fluctuations on the stability of this system. We also analyze the effects of thermal fluctuations on the criticality of the hyperscaling-violation background.     

Rapid, one-pot synthesis of highly-soluble carbon nanotubes functionalized by L-arginine

Functionalization of carbon nanotubes (CNTs) is a necessary step to exploit their valuable properties. Due to having several steps and especially acid treatment, most of current methods of functionalization result in irrecoverable defects on CNTs structure. Here, multiwalled carbon nanotubes (MWCNTs) were functionalized with L-arginine in a simple, one-pot and rapid microwave-assisted technique without any acid treatment step. The CNT functionalities were analyzed with infrared spectroscopy, thermogravimetric analysis, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results confirmed the covalent functionalization of L-arginine with very low defects on CNTs. Also it is found that increase of input powers of microwave in the range 500–900 W, monotonically increase the degree of functionalization. The maximum dispersibility of MWCNT was found ～1.03 mg/mL corresponding to 900 W irradiation. Accounting considerable low treatment time, the method may be applied for large-scale solubilization of MWCNTs in an industrial scale.     

Efficient computation of adiabatic populations in multi-mode Jahn-Teller systems through the use of effective vibrational modes

A highly efficient scheme for computing adiabatic electronic populations in multi-mode Jahn-Teller systems is presented. It relies on the transformation to an effective-mode vibrational basis in which the relevant quantities depend on the coordinates of a single mode only. In this way, the generally tedious numerical evaluation of high-dimensional integrals is avoided and replaced by one-dimensional integrations. The effective-mode scheme is applied to a variety of two-mode and three-mode Jahn-Teller systems and gives a typical speedup of about two to three orders of magnitude as compared to the direct evaluation of the adiabatic populations. The gain grows rapidly with the numbers of modes.     

Mammalian cell viability in electrospun composite nanofiber structures

Incorporation of mammalian cells into nanofibers (cell electrospinning) and multilayered cell-nanofiber structures (cell layering) via electrospinning are promising techniques for tissue engineering applications. We investigate the viability of 3T3-L1 mouse fibroblasts after incorporation into poly(vinyl alcohol) nanofibers and multilayering with poly(caprolactone) nanofibers and analyze the possible factors that affect cell viability. We observe that cells do not survive cell electrospinning but survive cell layering. Assessing the factors involved in cell electrospinning, we find that dehydration and fiber stretching are the main causes of cell death. In cell layering, the choice of solvent is critical, as residual solvent in the electrospun fibers could be detrimental to the cells.