Plasma Assisted Synthesis and Physicochemical Characterizations of Ni–Co/Al2O3 Nanocatalyst Used in Dry Reforming of Methane

To assess the effects of plasma treatment a Ni–Co/Al₂O₃ nanocatalyst (10 % Ni and 3 % Co) was prepared via impregnation method followed by treatment with a non-thermal plasma to be investigated in a catalytic dry reforming of methane. The impregnated and plasma-treated nanocatalysts were characterized using XRD, FESEM, EDX, TEM, BET, FTIR, and XPS techniques. The XRD patterns confirmed the presence of nickel as NiO and NiAl₂O₄ and cobalt as Co₃O₄ on alumina support. Small NiO, NiAl₂O₄, and Co₃O₄ crystals observed in plasma-treated nanocatalyst, exhibited a good dispersion of active phase in this catalyst. The average particles size in plasma-treated sample obtain by FESEM micrograph were shown to be smaller than that of impregnated sample and the morphology was more homogenous and relatively agglomeration-free in plasma-treated Ni–Co/Al₂O₃ nanocatalyst. According to BET analysis, specific surface area of plasma-treated sample was 58 % higher than the non-treated catalyst. TEM analysis showed that particles of active phase were fairly small and well-dispersed on Al₂O₃ as a result of the plasma treatment. Better dispersion of active metal on the surface of plasma-treated sample was confirmed by XPS analysis. The plasma-treated sample showed higher yield and conversion at all temperature ranges investigated and was more resistant to coke formation compared to the non-treated sample. The results from the characterization and reaction studies suggests that plasma treatment may be a promising method for obtaining more active and stable nanocatalysts for dry reforming of methane.     

Electrochemical Behavior of Glucose Oxidase Immobilized on Pd‐Nanoparticles Decorated Ionic Liquid Derived Fibrillated Mesoporous Carbon

Pd nanoparticles with an average diameter of 5 nm were decorated on the surface of ionic liquid derived fibrillated mesoporous carbon (IFMC) to prepare a novel nano‐hybrid material (Pd@IFMC). Thereafter, glucose oxidase was immobilized on Pd@IFMC modified glassy carbon electrode to fabricate an enzymatic glucose biosensor. A pair of well‐defined redox peaks was recorded for direct electron transfer of the immobilized glucose oxidase at the formal potential of ? 0.418 V with a peak to peak separation of 25 mV. Electron transfer rate constant of was calculated to be 14.6 s^?1. The response of fabricated biosensor was linear towards glucose concentration.     

Performance enhancement of thin‐film composite membranes in water desalination process by wood sawdust

In this study, polysulfone/wood sawdust (PSf/WSD) mixed matrix membrane (MMM) was prepared as a novel substrate layer of thin‐film composite (TFC) membrane in water desalination. The main aim was to evaluate how different amounts of WSD (0‐5 wt%) and PSf concentrations (12‐16 wt%) in the porous substrate affect the properties of the final TFC membranes in the separation of organic and inorganic compounds. Morphological and wettability studies demonstrated that the addition of small amount of WSD (less than or equal to 1 wt%) in the casting solution resulted in more porous but similar hydrophobic substrates, while high loading (greater than or equal to 2 wt%) of WSD not only changed the substrate wettability and morphology but also increased and decreased the swelling and mechanical properties of substrate layer. Therefore, PA layer formed thereon displayed extensively varying film morphology, interfacial properties, and separation performance. Based on approximately stable permeate flux (ASPF) and apparent salt rejection efficiency (ASRE), the best TFC membrane was prepared over the substrate with 12 to 14 wt% of PSf and around 0.5 to 1 wt% of WSD. Although notable improvements in permeate flux were obtained by adding a small amount of sawdust, the results clearly indicate that the salt rejection mechanism of TFC membrane was different from the glycerin rejection mechanism. Furthermore, durability results of TFC membranes showed that in continuous operation for 30 days, TFC‐14/0.5 and TFC‐14/01 have the maximum plateau levels of stable permeate flux and salt rejection among the all TFC membranes.     

Construction of a new Cu2+ coated wire ion selective electrode based on 2-((2-(2-(2-(2-hydroxy-5-methoxybenzylidene amino)phenyl)disufanyl)phenylimino)methyl)-4-methoxyphenol Schiff base

In this article a new coated platinum Cu²⁺ ion selective electrode based on 2-((2-(2-(2-(2-hydroxy-5-methoxybenzylideneamino)phenyl)disufanyl)phenylimino) methyl)-4-methoxyphenol Schiff base (L₁) as a new ionophore is described. This sensor has a wide linear range of concentration (1.2 × 10⁻⁷-1.0 × 10⁻¹ mol L⁻¹) and a low detection limit of 9.8 × 10⁻⁸ mol L⁻¹of Cu(NO₃)₂. It has a Nernstian response with slope of 29.54 ± 1.62 mV decade⁻¹ and it is applicable in the pH range of 4.0-6.0 without any divergence in potentioal. The coated electrode has a short response time of approximately 9 s and is stable at least for 3.5 months. The electrode shows a good selectivity for Cu²⁺ ion toward a wide variety of metal ions. The proposed sensor was successfully applied for the determination of Cu²⁺ ion in different real and environmental samples and as indicator electrode for potentiometric titration of Cu²⁺ ion with EDTA.     

A generalization of k-Cohen–Macaulay simplicial complexes

For a positive integer k and a non-negative integer t, a class of simplicial complexes, to be denoted by k-CM _t , is introduced. This class generalizes two notions for simplicial complexes: being k-Cohen–Macaulay and k-Buchsbaum. In analogy with the Cohen–Macaulay and Buchsbaum complexes, we give some characterizations of CM _t (=1?CM _t ) complexes, in terms of vanishing of some homologies of its links, and in terms of vanishing of some relative singular homologies of the geometric realization of the complex and its punctured space. We give a result on the behavior of the CM _t property under the operation of join of two simplicial complexes. We show that a complex is k-CM _t if and only if the links of its non-empty faces are k-CM _t?1. We prove that for an integer s≤d, the (d?s?1)-skeleton of a (d?1)-dimensional k-CM _t complex is (k+s)-CM _t . This result generalizes Hibi’s result for Cohen–Macaulay complexes and Miyazaki’s result for Buchsbaum complexes.     

Darbo type fixed and coupled fixed point results and its application to integral equation

We propose two new notion of contraction mappings involving measure of noncompactness in the frame work of Banach space and derive some basic Darbo type fixed and coupled fixed point results. The results are correlated with the classical Banach fixed point theorems. Further we show the applicability of obtained results to the theory of integral equations following a concrete example which illustrate the application part.