Multiplier completion of Banach algebras with application to quantum groups

Archiv der Mathematik - Let $${{\mathcal {A}}}$$ be a Banach algebra and let $$\varphi $$ be a non-zero character on $${{\mathcal {A}}}$$ . Suppose that $${{\mathcal {A}}}_M$$ is the closure of the...     

A series of 1,8-dioxooctahydroxanthenes are prepared using trichloroisocyanuric acid

A series of aromatic aldehydes are turned in to 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthene derivatives using trichloroisocyanuric acid(TCCA) as the catalyst.     

Comparison of the application of Debye-Huckel and specific ion interaction theories for the complexation of tungsten(VI) with ethylenediaminediacetic acid

Equilibrium of the reaction of tungsten(VI) with ethylenediaminediacetic acid (EDDA) has been investigated in aqueous solution of pH 7.5 and 25°C. All measurements have been carried out at different ionic strengths ranging from (0.1 to 1.0) mol dm⁻³ (NaClO₄). According to our results the metal to ligand ratio is 1: 1. Stability constants and stoichiometry of the complex have been determined from a combination of potentiometric and UV spectroscopic measurements. In this semi-empirical model, two parameters have been introduced in a Debye-Huckel type equation based on the Gauss—Newton nonlinear least-squares method and minimizing the sum of the squares of the errors. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Huckel type equation and Bronsted—Guggenheim—Scatchard specific ion interaction theory (SIT). Published in Russian in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 5, pp. 864–868. The article is published in the original     

Projective Synchronization of Piecewise Nonlinear Chaotic Maps

Theoretical and Mathematical Physics - With wide applications in secure data transmission and encryption, synchronization of chaotic systems is an interesting concept and has accordingly received...     

Application of calcium oxide as an efficient phase separation agent in temperature-induced counter-current homogenous liquid-liquid extraction of aflatoxins from dried fruit chips followed by high-performance liquid chromatography-tandem mass spectrometry determination

A temperature-induced counter-current homogenous liquid-liquid extraction procedure performed in a burette has been proposed for the isolation of aflatoxins B1, B2, G1, and G2 from various fruit chip samples. In this method, a homogenous solution of deionized water and cyclohexylamine is added to the solid sample and the resulted mixture is vortexed. In the following, the liquid phase is taken and passed through the burette filled with a mixture of calcium oxide (as a phase separation agent) and sand (to avoid clumping the calcium oxide). By doing so, the temperature of the solution is increased by hydration of calcium oxide and consequently, the homogenous state is broken and the aflatoxins are migrated into the resulted tiny droplets of cyclohexylamine. This phase is collected on the top of the solution owing to its low density with respect to an aqueous solution. Numerous parameters which can affect the efficiency of the suggested approach were evaluated and under the best situations, great repeatability, low limits of determination and quantification, and high extraction recoveries were acquired. In the end, the suggested approach was employed for the quantification of the selected aflatoxins in various fruit chips samples marketed in Tabriz City, Iran.     

Evaluation of activation energy conformity derived from model-free non-isothermal predictions and Arrhenius isothermal results

Organically modified montmorillonite (OMMT) was used as synergist to enhance the flame-retardant and mechanical properties of poly(butylene succinate)/intumescent flame retardant (PBS/IFR) composites. The flame-retardant, thermal degradation and combustion properties of PBS and its flame-retardant composites were characterized by limiting oxygen index (LOI) test, vertical burning (UL-94) test, thermogravimetric analysis, cone calorimeter and scanning electron microscopy, respectively. The results indicate that PBS/IFR composites exhibit excellent flame retardance when OMMT is at an appropriate content. PBS/IFR composite with 20 wt% IFR and 1.5 wt% OMMT has an LOI of 40.1% and can pass the UL-94 V0 rating. The synergistic effect between OMMT and IFR on the flame-retardant properties of PBS depends on the content of OMMT, and excessive OMMT diminish this synergistic effect. The possible flame-retardant mechanism of OMMT on PBS/IFR composite is proposed. The results of mechanical test also indicate that OMMT can effectively increase the notched impact strength of PBS/IFR composites.     

Experimental analysis of commercial LiFePO4 battery life span used in electric vehicle under extremely cold and hot thermal conditions

Journal of Thermal Analysis and Calorimetry - To widely commercialize electric vehicles more efforts for their life improvement seem extremely inevitable. Thermal conditions can have profound and...     

A Clean,Mild, and Selective Oxidation of Sulfides to Sulfoxides Using NaClO/H2SO4 in Aqueous Media

A range of sulfides can be selectively oxidized to the corresponding sulfoxides in good yields using NaClO/H₂SO₄ in both water and 50:50 water:EtOH as solvent. Two new compounds are reported that show a diastereoselective oxidation in 2-phenylthioalcohols with possible neighboring hydroxyl group participation with a logic proposed mechanism.     

Solvent-free coupling of aldehyde,alkyne, and amine over a versatile catalyst: Ag-functionalized mesoporous S,P-doped g-C3N4

In the present study, we introduce mesoporous g-C₃N₄/Ag co-doped with P and S which was designed and acquired by using mesoporous silica (SBA-15) as a hard templating agent and thiourea and chitosan phosphate as the dopants. The prepared catalyst was completely identified by FT-IR (Fourier-transform infrared spectroscopy), XRD (X-ray powder diffraction), FE-SEM (field-emission scanning electron microscopy), EDX (energy-dispersive spectroscopy), TEM (transmission electron microscopy), and Raman spectroscopy. The efficiency of the synthesized catalyst was evaluated toward the three-component coupling reaction, frequently named as A3 coupling. The higher activity of the prepared catalyst is because of the synergistic effects of phosphorus and sulfur co-doped together with Ag deposition. The desired products were achieved by an environmentally safe catalyst under the optimized conditions in high yields and short reaction time ranges.

     

Optimization of the transfer hydrogenation reaction of acetophenone on Ni@MOF-5 nanoparticles using response surface methodology

Research on Chemical Intermediates - In this study, the transfer hydrogenation reduction of acetophenone using supported nickel on MOF as catalyst was investigated. BBD and RSM were employed to...