4,032 research outputs found
Constitutive Models Based on Compressible Plastic Flows
The need for describing materials under time or cycle dependent loading conditions has been emphasized in recent years by several investigators. In response to the need, various constitutive models describing the nonlinear behavior of materials under creep, fatigue, or other complex loading conditions were developed. The developed models for describing the fully dense (non-porous) materials were mostly based on uncoupled plasticity theory. The improved characterization of materials provides a better understanding of the structual response under complex loading conditions. The pesent studies demonstrate that the rate or time dependency of the response of a porous aggregate can be incorporated into the nonlinear constitutive behavior of a porous solid by appropriately modeling the incompressible matrix behavior. It is also sown that the yield function which wads determined by a continuum mechanics approach must be verified by appropriate experiments on void containing sintered materials in order to obtain meaningful numbers for the constants that appear in the yield function
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3-1. Research Activities in 202
Alginate-Chitosan Particulate System for Sustained Release of Nimodipine
Purpose: The aim of this work was to prepare nimodipine-loaded alginate-chitosan beads for sustained drug release.Methods: Nimodipine-loaded alginate-chitosan beads were prepared by ionic gelation method using various combinations of chitosan and Ca2+ as cations and alginate as anion. The swelling ability and invitro drug release characteristics of the beads were studied at pH 1.2 and 6.8. Infra-red (IR) spectrometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), x-ray diffraction (XRD), and atomic absorption spectroscopy (AAS) were also applied to investigate thephysicochemical characteristics of the drug in bead formulations.Results: The surface morphology, size, and drug loading of the beads varied with increase in the concentration of chitosan and calcium chloride in the gelation medium. The swelling ability of the beadsin different pH media was dependent on the presence of a polyelectrolyte complex in the beads and the pH of the media. Both calcium alginate beads and the beads treated with chitosan failed to release thedrug at pH 1.2 over the period of study. On the other hand, at pH 6.8, calcium alginate beads released approx. 96 % of drug in 6 h, but treatment of the beads with chitosan lowered drug release to 73 %.Drug release mechanism was either “anomalous transport” or “case-II transport”. Data from characterisation studies indicate that there was no significant change in the physical state of the drug inthe bead formulation
Feminism in the view of tamil women writers
Feminism is a movement which intends to solve the problems of women in all spheres of life. Through feminism significant change can be brought about in politics, culture, economy, spirituality etc at world level. Feminism does not mean ensuring the rights of women. It means readically changing the society for the betterment of all the human beings. Women are very much oppressed in society, office and family. Mutual understanding of men and women in all dimensions is indispensable to foil the insult and injustice meted out to the women fold to a significant extent. Feminism refers to the struggle of women for equal rights in a peaceful way. Bama’s first noval Karukku is the first Dalit Novel in Tamil literature. Women endowed with education along can come out from the darkness of ignorance to the radiant light of radical thoughts. Only such women can ignite the spark of reformation in the women oppressed society. This is the consensus of the Tamil women writers
New Measurements with Stopped Particles at the LHC
Metastable particles are common in many models of new physics at the TeV
scale. If charged or colored, a reasonable fraction of all such particles
produced at the LHC will stop in the detectors and give observable out of time
decays. We demonstrate that significant information may be learned from such
decays about the properties (e.g. charge or spin) of this particle and of any
other particles to which it decays, for example a dark matter candidate. We
discuss strategies for measuring the type of decay (two- vs three-body), the
types of particles produced, and the angular distribution of the produced
particles using the LHC detectors. We demonstrate that with O(10-100) observed
decay events, not only can the properties of the new particles be measured but
indeed even the Lorentz structure of the decay operator can be distinguished in
the case of three-body decays. These measurements can not only reveal the
correct model of new physics at the TeV scale, but also give information on
physics giving rise to the decay at energy scales far above those the LHC can
probe directly.Comment: 31 pages, 6 figures. References added, updated to reflect recent
experimental results, version accepted for publication in Physical Review
Documentary of Woody flora and its usage in Maruthamalai Hills of the Southern Western Ghats of Coimbatore district, India
The present study described the occurrence of woody species and its usage inMaruthamalai Hills of the southern Western Ghats. A total of 119 species were collected ofwhich one individual categorized as gymnosperm and the remaining 118 individualscategorized as an angiosperms. Among the life habit the trees are the dominant species (86)other than shrubs (28) and lianas (5). The Fabaceae, Mimosaceae, Caesalpiniaceae andBignoniaceae are the dominant families of woody flora of the Maruthamalai Hills. Theimportance of recording the usage of plants in this region is imperative because of rapid lossof forest wealth and traditional wisdom. In view of the various resources use, habitatuniqueness and anthropological pressure on the forest resources, the need for conservation isstressed
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