In this research, a semi empirical approach has been suggested for calculating the activation energyof unimolecular thermal decomposition of vinyl ethers yielding saturated products. The calculationprocedure is based on the use of molecular mechanics (MM) methods. These methods which involvethe construction of the transition state for a molecule mainly consider the formation of a “HydrogenBridg...

The temperature change of the fractional dissociation of imidazole (alpha-imidazole) in resting human lower leg muscles was measured noninvasively using (1)H-nuclear magnetic resonance spectroscopy at 3.0 and 1.5 T on five normal male volunteers aged 30.6 +/- 10.4 yr (mean +/- SD). Using (1)H-nuclear magnetic resonance spectroscopy, water, carnosine, and creatine in the muscles could be simulta...

The aim of this work is to probe the influence of nanoclay and turmeric spends content on microcrystalline of vinyl ester hybrid nanocomposites. A series of vinyl ester hybrid nanocomposites have been fabricated with varying amounts of TS viz., 0, 2.5, 5, 7.5 and 10 % w/w along with 2% nanoclay. The microcrystalline parameters such as crystallite size and lattice strain of vinyl ester hybrid na...

The mechanism of imidazole-induced contraction on the bovine tracheal smooth muscle was investigated. Imidazole induced muscle contraction in a concentration-dependent manner on bovine, porcine and guinea-pig tracheas, but not in rat or mouse. In bovine tracheas, imidazole was cumulatively applied and induced muscle tension and increasesd intracellular Ca2+ level in a concentration -dependent m...

hydrolysis of ethylene-vinyl acetate copolymer in alkaline conditions using two systems of naoh/methanol and koh/isopropanol has been studied and the formation of ethylene-vinyl alcohol copolymer was systematically examined using nmr spectroscopy and dsc measurements. vinyl acetate weight percentage and the degree of hydrolysis were calculated from nmr spectroscopy and it is shown that hydrolys...

N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentra...

A set of mild processes for the conversion of vinyl cyclopropyl diazo ketones to highly functionalized cycloheptadienones and vinyl cyclopentenones by use of a target-inspired tandem Wolff/Cope rearrangement sequence is described. A divergent reaction course of the vinyl cyclopropyl diazo ketone substrates under sono- or photochemical activation provides good to excellent yields (55-98%) of the...

A highly sensitive carbon dot-imidazole (CD-imidazole) nanoprobe is prepared through covalently conjugating imidazole group onto the surface of carbon dots for water fluorescence. In organic solvents, quenching of fluorescence occurs via photoinduced electron transfer (PET) process from the imidazole nitrogen to the CD acceptor. Addition of a trace amount of water into CD nanocomposites in vari...

the thermal decomposition of 86 % vinyl chloride 14 % vinyl acetate copolymer wasstudied by the conductometry technique in the presence of nitrogen. the kinetics of stability andthermal degradation of vinyl chloride- co- vinyl acetate (pvc- co- pvac) copolymer withcopper, copper oxide and tricalcium dicitrate (st) were investigated at various temperatures (150-180 oc ) in solution. the rate coe...

To improve the damping properties of rubbers, organic tackifiers such as hydrocarbon resins, rosin esters, and polyterpenes are often incorporated to increase intermolecular friction rubber, thus increasing energy dissipation (damping) during dynamic loading. However, this is at expense cross-linking density mechanical rubbers. Ionic cross-links introduce unique a combination reinforcement high...