The densities and viscosities of the binary mixtures of JP-10 + n-octane and JP-10 + n-decane were determined from T = 293.15 K to T = 313.15 K at atmospheric pressure, over the entire composition range. Excess volume V m E of the binary mixtures was calculated. The experimental data indicate that the addition of n-alkane has a distinct effect on the density and viscosity of JP-10, and V m E values of the binary systems are negative. Experimental data were fitted to the Redlich−Kister equation, and the adjustable parameters and the standard deviations between experimental and calculated values were estimated. Conclusions were qualitatively discussed in terms of molecular interactions. The viscosity data have been correlated with several semiempirical equations, and the Grunberg−Nissan equation gives satisfactory results.

Densities and viscosities of exo-tetrahydrodicyclopentadiene + n-undecane and exo-tetrahydrodicyclopentadiene + n-tetradecane were measured at different temperatures of (293.15, 298.15, 303.15, and 313.15) K and atmospheric pressure over the entire composition range. The excess molar volumes V m E and deviations in viscosity δη for the mixtures were calculated from the experimental data and fitted to the Redlich-Kister equation, and the regression coefficients and the standard deviations of the fits were given. The viscosity data were correlated with several semiempirical equations, and the double-parameter McAllister equation gives satisfactory results.

No abstract

While aging is associated with increased knowledge, it is also associated with decreased semantic integration. To investigate brain activation changes during semantic integration, a sample of forty-eight 25–75 year-old adults read sentences with high cloze (HC) and low cloze (LC) probability while functional magnetic resonance imaging was conducted. Significant age-related reduction of cloze effect (LC vs. HC) was found in several regions, especially the left middle frontal gyrus (MFG) and right inferior frontal gyrus (IFG), which play an important role in semantic integration. Moreover, when accounting for global gray matter volume reduction, the age-cloze correlation in the left MFG and right IFG was absent. The results suggest that brain structural atrophy may disrupt brain response in aging brains, which then show less brain engagement in semantic integration.

No abstract

Densities and viscosities of exo-tetrahydrodicyclopentadiene + n-butanol and exo-tetrahydrodicyclopentadiene + n-pentanol were investigated over the whole composition range at several temperatures, (293.15, 298.15, 303.15, and 313.15) K, and atmospheric pressure. The excess molar volumes V m E for the mixtures were calculated based on these experimental data. The calculated quantities of V m E were fitted to the Redlich−Kister type polynomial equation, and the regression coefficients and the standard deviations of the fits were given. Several semiempirical equations were used to correlate the viscosity data, and the double-parameter McAllister equation gives satisfactory results.

No abstract

JP-10 has significant sensible heat sink capacities and may undergo endothermic chemical cracking for hypersonic aircraft applications without the problems associated with cryogenic fuels. Chemical initiators may accelerate the rate of cracking reactions and reduce the temperatures in a hypersonic aircraft heat exchanger/reactor. On the other hand, with the addition of an initiator some basic properties of JP-10 may change, such as volatility, which is directly related with ignition performance and combustion problems. Tributylamine (TBA) can be used as an effective initiator. Therefore, TBA and JP-10 blended fuel, as a potential fuel for hypersonic aircrafts, is worthwhile for further study. In the present work, the bubble-point vapor pressures and equilibrium temperatures for mixtures of JP-10 and TBA with different mass fractions were measured by comparative ebulliometry with inclined ebulliometers. Vapor pressures and equilibrium temperatures were correlated by Antoine’s equation with satisfactory precision. The bubble-point lines of pressure versus composition at different temperatures and temperature versus composition at different pressures were obtained. The mixtures exhibit positive deviations from Raoult’s law. It follows that the addition of TBA does not have a distinct effect on the vapor pressure and the phase equilibrium behavior of JP-10.