ABSTRACT
Densities (ρ12) and viscosities (η12) of binary mixtures of alkylethanoates, + cyclohexane, benzene, 1,4-dimethylbenzene and 1,3,5-trimethylbenzene have been measured over the whole mole fractions range at atmospheric pressure and temperature 308.15 K. Deviations of experimental viscosities from the linear mixing rule (Δη) for binary mixtures of the esters and cyclohexane are large and negative. Δη values are less and negative for binary mixtures of esters and aromatic hydrocarbons except binary mixtures of n-propylethanoate and benzene which show less positive Δη values. Δη values for binary mixtures of ethylethanoate + 1,4-dimethylbenzene, +1,3,5-trimethylbenzene and n-propylethanoate +1,4-dimethylbenzene are both less negative and less positive. Δη values are fitted into Redlich-Kister polynomial equation and standard deviations, σ of Δη for all the binary mixtures are reported. Several viscosity equations are critically analysed. The strengths of molecular interactions are discussed on the basis of Grunberg-Nissan interaction parameters.
ABSTRACT
Densities and ultrasound velocities for the binary mixtures of 1-bromobutane+benzene and 1,4-dimethylbenzene and of 1-bromopentane+cyclohexane and benzene have been measured at 308.15 K. Adiabatic compressibilities (beta(ad)), and Wada's constants (W) have also been evaluated as a function of composition. The ultrasound velocities decrease, attains a minimum and then increase with increase in mole fractions of hydrocarbons in the binary mixtures except in the case of 1-bromopentane+benzene binary mixtures where the variation is just the reverse. Dependence of adiabatic compressibilities with mole fractions of hydrocarbons is sigmoid. The non-ideal behaviour of the systems studied is explained on the basis of dipole-induced dipole interactions.
Subject(s)
Alkanes , Hydrocarbons, Brominated , Hydrocarbons , UltrasonicsABSTRACT
This article examines the prevalence of age-related diseases in different socioeconomic and demographic groups. The study is based on a sample of 267 aged persons (> 60 years) collected through a survey entitled "Aging and Health Conditions in Rural Area-A Sample Survey, 1990" conducted in the rural areas of the Varanasi district of Uttar Pradesh, a northern province of India. Various socio-behavioral factors are found to play a significant role in determining the health conditions of aged people. Also, illiteracy and poverty are found to have their own impact on health during aging. It is also noted that due to adverse familial relationships, many stress-related disorders occur which may result in the poor health of the elderly. Demands for old age pensions were made by most of the elderly people in the sample.
PIP: As part of a broader study of aging and health conditions in rural India, 267 persons over 60 years old from Uttar Pradesh's Varanasi district were interviewed in 1990. Overall, 37% of men and 70% of women rated their health condition as "bad." The incidence of illness after age 60 years was 77% among women and 61% among men. Most common were chest problems such as asthma, tuberculosis, and bronchitis. The percentage of unhealthy persons was slightly lower among illiterates and those with a university education than men and women with primary or middle school educational levels. These educational differences are presumed to reflect class-based occupational histories. In general, those with middle levels of education were employed in household industry or businesses with high exposure to disease. Men and women with unsatisfactory, conflictual family relationships also experienced increased health problems. Although respondents expressed the view that the shift from joint to nuclear family systems has lowered the status of the elderly, 62% maintained they did not need any further support from their families. A demand for some type of old age pension from the government was proposed, however. These findings suggest a need for increased social responsibility for the health and well-being of India's aging population.
