Polymerization of acrylonitrile. Kinetics of the reaction initiated by the Ce(IV)/thioacetamide redox system

Vinyl polymerization of acrylonitrile initiated by the Ce(IV)/thioacetamide redox system has been investigated in aqueous sulfuric acid in the temperature range of 10–20°C. The rate of polymerization (R_p) and the rate of Ce(IV) disappearance (?R_Ce) were measured. The effect of certain water-soluble organic solvents, added electrolytes, and aromatic and heterocyclic organic nitrogen compounds on the rate of polymerization has been investigated. Depending on the experimental results, we have suggested a suitable reaction scheme for the system which involves the production of initiating radicals from the oxidation of thioacetamide (TAm) by ceric ion and the termination of the polymer chain by metal ions.     

A Sensitive HPTLC Method for Estimation of Amentoflavone,a Bioactive Principle from Biophytum sensitivum (Linn.) DC. and Putranjiva roxburghii Wall.

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive high-performance thin-layer chromatographic (HPTLC) method has been developed for estimation of amentoflavone, an...     

黏性流体与热弹性微极蜂窝结构介质界面上受倾斜荷载作用时的弹性动力分析

研究倾斜荷载作用在黏性流体与热弹性微极蜂窝结构固体界面上时,荷载倾斜角的影响．假设倾斜荷载是法向荷载和切向荷载的线性组合．为求解该问题,对时间变量进行Laplace变换,对空间变量进行Fourier变换．通过引入势函数,获得了变换域中应力、温度分布和压力的表达式．利用数值逆变换技术,求得问题的物理解．同时,得到了频域中的表达式,以及变量适当变化时稳态情况下的表达式．用图形显示不同荷载源和荷载倾角变化时的响应．并且讨论了一些特殊情况．     

Para Substituted Benzaldehydes as Expedient Reagents for the Oxidative Aromatization of Hydroquinoline

A Cannizzaro‐type reaction of tetrahydro‐5(1H)‐quinolinones with para substituted benzaldehydes in the presence of a base formed the corresponding quinoline and aryl methanol rather than arylidene derivatives because of the oxidation of tetrahydroquinoline and reduction of benzaldehydes as a result of unprecedented hydride transfer from tetrahydroquinoline to arylaldehydes. The reaction proceeds best with the participation of substituents with +M effect in substrate molecule.     

Role of Impurity Precipitates on Microhardness of KBr:Ba2+ Crystals

Microhardness of KBr crystals doped with various concentration of Ba²⁺ have been investigated in the asgrown state and after quenching from various elevated temperatures. It is observed that hardness increases with increase in impurity concentration and at high concentration the hardness starts decreasing. Microstructural investigations have showed the formation of visible precipitates at high concentrations. The heat treatment studies showed that in crystals quenched from elevated temperatures the visible precipitates dissociate and hardness increases.     

Synthesis,In Vitro Biological Screening,and In Silico Computational Studies of Some Novel Imidazole‐2‐thiol Derivatives

Substituted imidazole analogues 2‐((5‐acetyl‐4‐methyl‐1‐phenyl‐1H‐imidazole‐2‐yl)thio)‐N‐phenylacetamides ( 3a – 3m ) have been synthesized from 1‐[1‐(phenyl)‐2‐mercapto‐4‐methyl‐1H‐imidazol‐5‐yl]‐ethanone ( 1a – 1e ) and 2‐chloro‐N‐phenylacetamide ( 2a – 2i ) in the presence of potassium carbonate as a catalyst in dimethylformamide under microwave irradiation as well as conventional method. Structures of the obtained compounds have been confirmed by advance spectroscopic techniques such as IR, ¹H NMR, ¹³C NMR, and mass spectrometry. All the synthesized compounds were tested for their in vitro antimicrobial and antituberculosis activities. Good antibacterial molecules were further screened for the bacterial resisted cell line, from which compound 3b shows maximum inhibition. In silico molecular docking study was carried out to discover the binding affinity of synthesized compounds with active site of transferase (PDB ID: 1HNJ) and antibiotic resistance (PDB ID: 1W3R) protein. Moreover, molecular dynamics study of the 3b ‐1W3R complex has also been performed, as 3b has a good antibacterial activity as compared with other.     

A Sensitive HPTLC method for Estimation of Swertiamarin in Enicostemma littorale Blume,Swertia chirata (Wall) Clarke,and in formulations containing E. littorale

JPC – Journal of Planar Chromatography – Modern TLC - Swertiamarin is a secoiridoid glucoside present in members of the Gentianaceae family, including Swertia chirata (Wall) Clarke, S....     

Use of polyacrylamide-grafted<Emphasis Type="Italic"> Plantago psyllium</Emphasis> mucilage as a flocculant for treatment of textile wastewater

The chemical modification of Plantago psyllium mucilage (Psy), an anionic polysaccharide, was done by grafting polyacrylamide (PAM) chains to prepare a graft-copolymer (Psy-g-PAM). It was synthesized in the presence of nitrogen using ceric ammonium nitrate–nitric acid redox initiator and characterized by IR spectroscopy, scanning electron microscopy and viscosity measurements. This grafted copolymer was tested for its flocculation efficiency in textile wastewater by the standard Jar test method. The effects of polymer concentration, pH and contact time on the percentage removal of solid wastes [total dissolved solids (TDS) and suspended solids (SS)] and color from textile effluent are reported. The optimum dose was found to be 1.6 mg l^–1, at which maximum solid removal (SS and TDS) was seen. The most suitable pH for TDS and color removal was neutral (7.0) and for SS removal alkaline pH (9.2) was found to be most suitable. The optimum treatment duration for solid waste removal was 5 h. The X-ray diffraction analysis of Psy-g-PAM and solid waste before and after treatment suggests the interaction of the solid waste and Psy-g-PAM copolymer.