Collective dynamics of large aspect ratio dusty plasma in an inhomogeneous plasma background: Formation of the co--rotating vortex series

In this paper, the collective dynamics of the large aspect ratio dusty plasma is studied over a wide range of discharge parameters. An inductively coupled diffused plasma, which creates an electrostatic trap to confine the negatively charged grains, is used to form a large volume (or large aspect ratio) dusty plasma at low pressure. For introducing the dust grains into the potential well, a unique technique using a secondary DC glow discharge plasma is employed. The dust dynamics is recorded in a 2-dimension (2D) plane at a given axial location. The dust fluid exhibits wave like behavior at low pressure (p < 0.06 mbar) and high rf power (P > 3 W). The mixed motion, waves and vortices, are observed at an intermediate gas pressure(p = 0.08 mbar) and low power (P < 3 W). Above the threshold value of gas pressure (p > 0.1 mbar), the clockwise and anti-clockwise co-rotating vortex series are observed on the edges of the dust cloud, whereas the particles in central region show the random motion. These vortices are only observed above a threshold width of the dust cloud. The streaming ions are considered the available free energy source to excite the waves in dust grain medium. The occurrence of the co-rotating vortices is understood on the basis of the charge gradient of dust particles which is orthogonal to the gravity. The charge gradient is a consequence of the plasma inhomogeneity from the central region to the outer edge of dust fluid. Since, a vortex has the characteristic size in the dissipative medium; therefore, a series of the co-rotating vortex on the both sides of dusty plasma is observed. The experimental results on the vortex formation and its multiplicity are compared to an available theoretical model and are found to be in close agreement.Comment: 12 pages, 10 Figures. arXiv admin note: text overlap with arXiv:1701.0323

Safe abortion – Still a neglected scenario: A study of septic abortions in a tertiary hospital of Rural India

Background and Aims: In spite abortion has been legalized in India over three decades, unsafe abortion continues to be a significant contributor of maternal mortality and morbidity. The aim of the present study is to assess the magnitude of septic abortion in a tertiary care hospital over a period of three years with a special emphasis on maternal mortality and morbidity and various surgical complications. Settings and Design: Retrospective study of patients who were admitted with unsafe abortions over a three year period from 2005 to 2008 in a tertiary teaching Hospital of Rural India. Materials and Methods: Hospital records of the patients who were admitted with unsafe abortion in three years (2005-2008) were reviewed to evaluate the demographic and clinical profile in relation to age, parity, marital status, indication of abortion , the methods of abortion ,qualification of abortion provider complications and maternal mortality. Results: Unsafe abortion constitutes 11.6% ( n=132) of total abortion cases admitted over 3 years. Majority of women (70.45%) were in their thirties, married (89%).Sixty percent wanted abortion for birth spacing. Abortion methods included various primitive methods (30%) but majority by dilatation and evacuation. About 60% of abortionists were unqualified. Majority of women admitted with serious complications like peritonitis (70%), visceral injuries (60%), hemorrhagic and septic shock, renal failure (17.4%), and life threatening conditions like DIC, hepatic failure and encephalopathy. A total of 231 women died of unsafe abortion making it 12.55% of total maternal mortality in our institution. Out of 73 women requiring laparotomy, 22% were done within 24 hours of admission and majority (49%) were performed beyond 24-48 hours. Interestingly no women died when early aggressive surgery was done. Conclusion: The present study confirms that unsafe abortion is a great neglected health care problem leading to a considerable loss of maternal lives. Education and accessibility of contra caption, readily available, quality abortion services by trained abortion providers remain the key to limit mortality and morbidity arising from unsafe abortion

Detailed simulation results for some wealth distribution models in Econophysics

In this paper we present detailed simulation results on the wealth distribution model with quenched saving propensities. Unlike other wealth distribution models where the saving propensities are either zero or constant, this model is not found to be ergodic and self-averaging. The wealth distribution statistics with a single realization of quenched disorder is observed to be significantly different in nature from that of the statistics averaged over a large number of independent quenched configurations. The peculiarities in the single realization statistics refuses to vanish irrespective of whatever large sample size is used. This implies that previously observed Pareto law is essentially a convolution of the single member distributions.Comment: 9 pages, 6 figure