Experimental Study of Free Energy of Activation of Flow and Grunberg-Nissan Parameters in Binary Liquid Mixtures

The binary mixtures of cabontetrachloride with isobutylmethylketone and benzaldehyde were studied at 308.15 by measuring viscosities and densities. The derived and excess viscosities, activation energy of flow and Grunberg-Nissan parameters have been calculated. It was found that these parameters are satisfactorily used to predict the strength and nature of molecular interactions. It was found that the strength of interactions in the systems studied is in the following order: CCl4 + IBMK>CCl4 + BD Keywords: Binary liquid; benzaldehyde; carbontetrachloride DOI: 10.3126/bibechana.v6i0.3932 BIBECHANA Vol. 6, March 2010 pp.9-1

Experimental Study of Free Energy of Activation of Flow and Grunberg-Nissan Parameters in Binary Liquid Mixtures

The binary mixtures of cabontetrachloride with isobutylmethylketone and benzaldehyde were studied at 308.15 by measuring viscosities and densities. The derived and excess viscosities, activation energy of flow and Grunberg-Nissan parameters have been calculated. It was found that these parameters are satisfactorily used to predict the strength and nature of molecular interactions. It was found that the strength of interactions in the systems studied is in the following order: CCl4 + IBMK>CCl4 + BD Keywords: Binary liquid; benzaldehyde; carbontetrachloride DOI: 10.3126/bibechana.v6i0.3932 BIBECHANA Vol. 6, March 2010 pp.9-1

Structural study of liquid Sn-Tl alloys

The concentration fluctuations in long wavelength limit, Scc(0) and the Warren-Cowley short range order parameter (α1) are important microscopic functions which provide valuable information about the local arrangements of the constituent atoms in the alloy melts. In order to investigate the nature of atomic ordering in Sn-Tl alloy in the molten state at 723K, we have computed these functions using theoretical models. The models satisfactorily explain the small asymmetry observed in the experimental data of free energy of mixing of the alloy. The comparative study further reveals that the energy interaction parameters are temperature dependent and the Sn-Tl alloy is weakly interacting segregating system. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10379   BIBECHANA 11(1) (2014) 46-5

Structural study of liquid Sn-Tl alloys

The concentration fluctuations in long wavelength limit, Scc(0) and the Warren-Cowley short range order parameter (α1) are important microscopic functions which provide valuable information about the local arrangements of the constituent atoms in the alloy melts. In order to investigate the nature of atomic ordering in Sn-Tl alloy in the molten state at 723K, we have computed these functions using theoretical models. The models satisfactorily explain the small asymmetry observed in the experimental data of free energy of mixing of the alloy. The comparative study further reveals that the energy interaction parameters are temperature dependent and the Sn-Tl alloy is weakly interacting segregating system. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10379   BIBECHANA 11(1) (2014) 46-5

Hubble Space Telescope and ground-based observations of SN 1993J and SN 1998S: CNO processing in the progenitors

Ground-based and Hubble Space Telescope observations are presented for SN 1993J and SN 1998S. SN 1998S shows strong, relatively narrow circumstellar emission lines of N III-V and C III-IV, as well as broad lines from the ejecta. Both the broad ultraviolet and optical lines in SN 1998S indicate an expansion velocity of ∼7000 km s -1. The broad emission components of Lyα and Mg II are strongly asymmetrical after day 72 past the explosion and differ in shape from Hα. Different models based on dust extinction from dust in the ejecta or shock region, in combination with Hα from a circumstellar torus, are discussed. It is concluded, however, that the double-peaked line profiles are more likely to arise as a result of optical depth effects in the narrow, cool, dense shell behind the reverse shock than in a torus-like region. The ultraviolet lines of SN 1993J are broad, with a boxlike shape, coming from the ejecta and a cool, dense shell. The shapes of the lines are well fitted by a shell with inner velocity ∼7000 km s -1 and outer velocity ∼10,000 km s -1. For both SN 1993J and SN 1998S a strong nitrogen enrichment is found, with N/C ≈ 12.4 in SN 1993J and N/C ≈ 6.0 in SN 1998S. From a compilation of all supernovae with determined CNO ratios, we discuss the implications of these observations for the structure of the progenitors of Type II supernovae. © 2005. The American Astronomical Society. All rights reserved,.published_or_final_versio

Diarrhea, Pneumonia, and Infectious Disease Mortality in Children Aged 5 to 14 Years in India

Background: Little is known about the causes of death in children in India after age five years. The objective of this study is to provide the first ever direct national and sub-national estimates of infectious disease mortality in Indian children aged 5 to 14 years. Methods: A verbal autopsy based assessment of 3 855 deaths is children aged 5 to 14 years from a nationally representative survey of deaths occurring in 2001–03 in 1?1 million homes in India. Results: Infectious diseases accounted for 58 % of all deaths among children aged 5 to 14 years. About 18 % of deaths were due to diarrheal diseases, 10 % due to pneumonia, 8 % due to central nervous system infections, 4 % due to measles, and 12 % due to other infectious diseases. Nationally, in 2005 about 59 000 and 34 000 children aged 5 to 14 years died from diarrheal diseases and pneumonia, corresponding to mortality of 24?1 and 13?9 per 100 000 respectively. Mortality was nearly 50 % higher in girls than in boys for both diarrheal diseases and pneumonia. Conclusions: Approximately 60 % of all deaths in this age group are due to infectious diseases and nearly half of these deaths are due to diarrheal diseases and pneumonia. Mortality in this age group from infectious diseases, and diarrhea i

Child mortality from solid-fuel use in India: a nationally-representative case-control study

Abstract Background Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. Methods We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Results Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio (PR) boys: 1.30, 95%CI 1.08-1.56; girls: 1.33, 95%CI 1.12-1.58). More girls than boys died from exposure to solid fuels. Solid fuel use was also associated with non-fatal pneumonia (boys: PR 1.54 95%CI 1.01-2.35; girls: PR 1.94 95%CI 1.13-3.33). Conclusions Child mortality risks, from all causes, due to solid fuel exposure were lower than previously, but as exposure was common solid, fuel caused 6% of all deaths at ages 0-4, 20% of deaths at ages 1-4 or 128 000 child deaths in India in 2004. Solid fuel use has declined only modestly in the last decade. Aside from reducing exposure, complementary strategies such as immunization and treatment could also reduce child mortality from acute respiratory infections

The Paired Availability Design for Historical Controls

BACKGROUND: Although a randomized trial represents the most rigorous method of evaluating a medical intervention, some interventions would be extremely difficult to evaluate using this study design. One alternative, an observational cohort study, can give biased results if it is not possible to adjust for all relevant risk factors. METHODS: A recently developed and less well-known alternative is the paired availability design for historical controls. The paired availability design requires at least 10 hospitals or medical centers in which there is a change in the availability of the medical intervention. The statistical analysis involves a weighted average of a simple "before" versus "after" comparison from each hospital or medical center that adjusts for the change in availability. RESULTS: We expanded requirements for the paired availability design to yield valid inference. (1) The hospitals or medical centers serve a stable population. (2) Other aspects of patient management remain constant over time. (3) Criteria for outcome evaluation are constant over time. (4) Patient preferences for the medical intervention are constant over time. (5) For hospitals where the intervention was available in the "before" group, a change in availability in the "after group" does not change the effect of the intervention on outcome. CONCLUSION: The paired availability design has promise for evaluating medical versus surgical interventions, in which it is difficult to recruit patients to a randomized trial

Superlattices: problems and new opportunities, nanosolids

Superlattices were introduced 40 years ago as man-made solids to enrich the class of materials for electronic and optoelectronic applications. The field metamorphosed to quantum wells and quantum dots, with ever decreasing dimensions dictated by the technological advancements in nanometer regime. In recent years, the field has gone beyond semiconductors to metals and organic solids. Superlattice is simply a way of forming a uniform continuum for whatever purpose at hand. There are problems with doping, defect-induced random switching, and I/O involving quantum dots. However, new opportunities in component-based nanostructures may lead the field of endeavor to new heights. The all important translational symmetry of solids is relaxed and local symmetry is needed in nanosolids