Speeds of sound and isentropic compressibilities of binary mixtures containing trialkylamines with alkanes and mono-alkylamines at 303.15 and 313.15 K

Isentropic compressibilities ?S, and excess isentropic compressibilities ?SE have been determined from measurements of speeds of sound u and densities ? of 14 binary mixtures of triethylamine (TEA) and tri-n-butylamine (TBA) with n-hexane, n-octane, iso-octane, n-propylamine, n-butylamine, n-hexylamine and n-octylamine. The relative magnitude and sign of ?SE have been interpreted in terms of molecular interactions and interstitial accommodation. The values of ?SE for TEA + alkane are positive while for TBA + alkane are negative. The values of ?SE for TEA + primary amine become progressively less positive and eventually to negative with the increase in chain length of alkylamine. In case of TBA + primary amine, the values of ?SE increase from n-propylamine to n-butylamine, and then decrease with chain length of primary amine. The experimental speeds of sound u have been analyzed in terms of collision factor theory, free length theory and Prigogine–Flory–Patterson statistical theory of solutions.

Viscosity of binary mixtures of cycloalkane with cycloalkane, alkane and aromatic hydrocarbon at 303.15 K

The viscosity ? for eighteen binary mixtures cyclopentane + cyclohexane and + cyclooctane; cyclohexane + cycloheptane, + cyclooctane, + methylcyclohexane, + n-hexane, + n-heptane, + n-octane, + i-octane, + benzene, + toluene, + ethylbenzene, + p-xylene, and + propylbenzene; methylcyclohexane + n-hexane, + i-octane, and + benzene; and cyclooctane + benzene have been reported at 303.15 K over the entire range of composition. The viscosity deviations ?? and excess Gibbs energy of activation ?G*E of viscous flow based on Eyring's theory have been calculated. The effects of molecular sizes and shapes of the component molecules and of interaction energy in the mixture have been discussed. The viscosity data have been correlated with the equations of Grunberg and Nissan, Hind, McLaughlin and Ubbelohde, Tamura and Kurata, Katti and Chaudhri, McAllister, Heric and Brewer, and of Auslaender.

Speeds of sound, isentropic compressibilities, and excess molar volumes of cycloalkanes, alkanes and aromatic hydrocarbons at 303.15 K. II. Results for cycloalkanes+aromatic hydrocarbons

The speeds of sound u, isentropic compressibilities ?S, molar sound functions R, excess isentropic compressibilities ?SE and excess molar volumes VE for eight binary mixtures of cyclopentane, cyclohexane, cyclooctane and methylcyclohexane with benzene and of cyclohexane with toluene, ethyl benzene, p-xylene and propyl benzene at 303.15 K are reported. The effects of molecular sizes and shapes of the component molecules and of interaction energy in the mixture have been discussed. The Prigogine–Flory–Patterson theory has been applied to analyze the present binary mixtures along with the mixtures of cis- and trans-decalins with benzene and toluene taken from the literature.

Densities, speeds of sound, isentropic compressibilities, refractive indices and viscosities of binary mixtures of tetrahydrofuran with hydrocarbons at 303.15 K

Isentropic compressibilities, Rao's molar sound functions, molar refractions, excess isentropic compressibilities, excess molar volumes, viscosity deviations and excess Gibbs energies of activation of viscous flow for seven binary mixtures of tetrahydrofuran (THF) with cyclohexane, methylcyclohexane, n-hexane, benzene, toluene, p-xylene and propylbenzene over the entire range of composition at 303.15 K have been derived from experimental densities, speeds of sound, refractive indices and viscosities. The excess partial molar volumes of THF in different solvents have been estimated. The experimental results have been analyzed in terms of the Prigogine–Flory–Patterson theory.

Densities, speeds of sound, isentropic compressibilities, refractive indexes, and viscosities of tetrahydrofuran with haloalkane or alkyl ethanoate at T = 303.15 K

Isentropic compressibilities ?S, excess isentropic compressibilities image, excess molar volumes VE, viscosity deviations ??, and excess Gibbs energy of activation of viscous flow ?G*E for nine binary mixtures of C4H8O with CCl4, CHCl3, CHCl2CHCl2, 1-C6H13Cl, 1-C6H13Br, CH3CO2CH3, CH3CO2C2H5, CH3CO2C4H9, and CH3CO2C5H11 at 303.15 K have been derived from experimental densities ?, speeds of sound u, refractive indexes nD and viscosities ?. The limiting values of excess partial molar volumes of C4H8O at infinite dilution image in different solvents have been estimated. The results obtained for dynamic viscosity of binary mixtures were used to test the semi-empirical relations of Grunberg–Nissan, Tamura–Kurata, Hind–McLaughlin–Ubbelohde, Katti–Chaudhri, McAllister, Heric, and Auslaender. Finally, the experimental refractive indexes were compared with the predicted results for Lorentz–Lorenz, Dale–Gladstone, Eykman, Arago–Boit, Newton, Oster, Heller, and Wiener equations.

Speeds of sound, isentropic compressibilities, viscosities, and excess molar volumes of binary mixtures of alkanoates with tetra- and trichloromethanes at 303.15 K

Speeds of sound u, isentropic compressibilities ?S, viscosities ?, excess isentropic compressibilities ?SE, excess molar volumes VE, viscosity deviations ??, and excess Gibbs energies of activation ?G*E of viscous flow have been investigated for six binary mixtures of diethyl malonate, diethyl bromomalonate, and ethyl chloroacetate with tetra- and trichloromethane at 303.15 K. The values of ?SE, VE, ??, and ?G*E are highly dependent on the type of components involved and the composition curves are unsymmetrical. The results obtained for viscosity of binary mixtures were used to test the semi-empirical relations of Grunberg-Nissan, Tamura-Kurata, Hind-McLaughlin-Ubbelohde, Katti-Chaudhri, McAllister, Heric-Brewer and Auslaender. The experimental speeds of sound have been analyzed in terms of collision factor theory and free length theory of solutions.

Effects of intrahippocampal NAC(61-95) injections on memory in the rat and attenuation with vitamin E

Parkinson's disease (PD)-related dementia affects approximately 40% of PD patients and the severity of this dementia correlates significantly with the density of Lewy body (LB) deposition in the PD brain. Aggregated alpha-synuclein protein is the major component of LB's and the non-amyloid component (NAC) region of alpha-synuclein, residues 61-95, is essential for the aggregation and toxicity of this protein. The current study evaluated the effect of pre-aggregated NAC(61-95) injected into the CA3 area of the dorsal hippocampus of the brain on memory in the rat. Previous research has suggested that oxidative stress processes may play a role in the neuropathology of PD, therefore the effect of treatment with vitamin E, an antioxidant, was also evaluated. Male Sprague-Dawley rats were trained in two-lever operant chambers under an alternating-lever cyclic-ratio (ALCR) schedule of food reinforcement. When responding showed no trends, subjects were divided into four groups. Two groups were injected bilaterally into the dorsal hippocampus with aggregated NAC(61-95) (5 mu l suspension), and two groups were injected bilaterally into the dorsal hippocampus with sterile water (5 mu l). Subgroups were treated with either vitamin E (150 mg/kg in Soya oil) or vehicle (Soya oil) daily. Injection of NAC(61-95) induced memory deficits and vitamin E treatment alleviated these. In addition, NAC(61-95) injections induced activated astrocytes and chronic treatment with vitamin E reduced the numbers of activated astrocytes. These results suggest that aggregated NAC(61-95) and associated oxidative stress, may play a role in the pathogenesis of cognitive deficits seen in PD-induced dementia. (C) 2009 Elsevier Inc. All rights reserved.

Mortuary ritual of fourth millennium BC Malta: the Zebbug tomb from the Brochtorff Circle (Gozo).

Malone, C.A.T., et al., including Trump, Bonanno, Stoddart, Gouder

WASP-30b: A 61 M Jup Brown Dwarf Transiting a V = 12, F8 Star

We report the discovery of a 61-Jupiter-mass brown dwarf (BD), which transits its F8V host star, WASP-30, every 4.16 days. From a range of age indicators we estimate the system age to be 1-2 Gyr. We derive a radius (0.89 ± 0.02 R Jup) for the companion that is consistent with that predicted (0.914 R Jup) by a model of a 1 Gyr old, non-irradiated BD with a dusty atmosphere. The location of WASP-30b in the minimum of the mass-radius relation is consistent with the quantitative prediction of Chabrier & Baraffe, thus confirming the theory.

Higher effort-reward imbalance and lower job control predict exit from the labour market at the age of 61 years or younger: Evidence from the English Longitudinal Study of Ageing

Background: We examined whether higher effort-reward imbalance (ERI) and lower job control are associated with exit from the labour market. 

Methods: There were 1263 participants aged 50-74 years from the English Longitudinal Study on Ageing with data on working status and work-related psychosocial factors at baseline (wave 2; 2004-2005), and working status at follow-up (wave 5; 2010-2011). Psychosocial factors at work were assessed using a short validated version of ERI and job control. An allostatic load index was formed using 13 biological parameters. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Exit from the labour market was defined as not working in the labour market when 61 years old or younger in 2010-2011. 

Results: Higher ERI OR=1.62 (95% CI 1.01 to 2.61, p=0.048) predicted exit from the labour market independent of age, sex, education, occupational class, allostatic load and depression. Job control OR=0.60 (95% CI 0.42 to 0.85, p=0.004) was associated with exit from the labour market independent of age, sex, education, occupation and depression. The association of higher effort OR=1.32 (95% CI 1.01 to 1.73, p=0.045) with exit from the labour market was independent of age, sex and depression but attenuated to non-significance when additionally controlling for socioeconomic measures. Reward was not related to exit from the labour market. 

Conclusions: Stressful work conditions can be a risk for exiting the labour market before the age of 61 years. Neither socioeconomic position nor allostatic load and depressive symptoms seem to explain this association.