Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-section

The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.Comment: Accepted for publication in ASME journal of Applied Mechanics. arXiv admin note: text overlap with arXiv:1108.1285v

Towards Social Security Systems in Japan Lessons for India

Japan has to restructure its social security systems fromtime to time for different reasons like a far more rapid aging of population , the slow down of long term economic growth and deteriorating equity in the inter-generational transfer of welfare .But even then, the basic elements remain the same .It si pertinent to see how and to whar extent japan’s social security systems could be translated in the case of India. As apreliminary analysis ,in section One, attempt has been made to summarize the distinctive features of social security systems in Japan.Section Two dwells upon the nature and problems of the social security systems in India. An endeavour has been made in Section three to articulate on the lessons for India. Final Section Four concludes and summarizes the main findings.It has ben observed that there are certain experiences that India can learn ,amongothers, the careful application of universal social security systems, the role of insurance policies,private-public synergies ,the role of the government and governance, the importance attached to social capital.Universal social security system, private–public partnership, Inter-generational Equity governance, social capital

Type IIA on a Compact Calabi-Yau and D=11 Supergravity Uplift of its Orientifold

Using the prescription of [1] for defining period integrals in the Landau-Ginsburg theory for compact Calabi-Yau's, we obtain the Picard-Fuchs equation and the Meijer basis of solutions for the compact Calabi-Yau CY_3(3,243) expressed as a degree-24 Fermat hypersurface AFTER resolution of the orbifold singularities. This is similar in spirit to the method of obtaining Meijer basis of solutions in [2] for the case wherein one is away from the orbifold singularities, and one is considering the large-base limit of the Calabi-Yau. The importance of the method lies in the ease with which one can consider the large AND small complex structure limits, as well as the ability to get the "ln"-terms in the periods without having to parametrically differentiate infinite series. We consider in detail the evaluation of the monodromy matrix in the large and small complex structure limits. We also consider the action of the freely acting antiholomorphic involution of [2],[3] on D=11 supergravity compactified on CY_3(3,243) x S^1 [4] and obtain the Kaehler potential for the same in the limit of large volume of the Calabi-Yau. As a by-product, we also give a conjecture for the action of the orientation-reversing antiholomorphic involution on the periods, given its action on the cohomology, using a canonical (co)homology basis. Finally, we also consider showing a null superpotential on the orientifold of type IIA on CY_3(3,243), having taken care of the orbifold singularities, thereby completing the argument initiated in [2].Comment: 45 pages, LaTex, 2 ps figures; v3: (Fort. der. Physik) Journal versio

A two zone model for the broad Iron line emission in MCG-6-30-15

We reanalyze the ASCA and BeppoSAX data of MCG-6-30-15, using a double zone model for the Iron line profile. In this model, the X-ray source is located around $\approx 10$ Schwarzschild radius and the regions interior and exterior to the X-ray source produce the line emission. We find that this model fits the data with similar reduced $\chi^2$ as the standard single zone model. The best fit inclination angle of the source ($i \approx 10^o$) for the medium intensity ASCA data set is compatible with that determined by earlier modeling of optical lines. The observed variability of the line profile with intensity can be explained as variations of the X-ray source size. That several AGN with broad lines have the peak centroid near 6.4 keV can be explained within the framework of this model under certain conditions. We also show that the simultaneous broad band observations of this source by BeppoSAX rules out the Comptonization model which was an alternative to the standard inner disk one. We thereby strengthen the case that the line broadening occurs due to the strong gravitational influence of a Black Hole.Comment: submitted to mnra