559 research outputs found
Structure and Rheology of the Defect-gel States of Pure and Particle-dispersed Lyotropic Lamellar Phases
We present important new results from light-microscopy and rheometry on a
moderately concentrated lyotropic smectic, with and without particulate
additives. Shear-treatment aligns the phase rapidly, except for a striking
network of oily-streak defects, which anneals out much more slowly. If
spherical particles several microns in diameter are dispersed in the lamellar
medium, part of the defect network persists under shear-treatment, its nodes
anchored on the particles. The sample as prepared has substantial storage and
loss moduli, both of which decrease steadily under shear-treatment. Adding
particles enhances the moduli and retards their decay under shear. The data for
the frequency-dependent storage modulus after various durations of
shear-treatment can be scaled to collapse onto a single curve. The elasticity
and dissipation in these samples thus arises mainly from the defect network,
not directly from the smectic elasticity and hydrodynamics.Comment: 19 pages inclusive of 12 PostScript figures, uses revtex, psfrag and
epsfig. Revised version, accepted for publication in Euro. Phys. J. B, with
improved images of defect structure and theoretical estimates of network
elasticity and scalin
ANTIPYRETIC ACTIVITY OF ANNONA PLANTS LEAVES ON BREWER'S YEAST INDUCED FEBRILE RATS
Objective: To evaluate and compare the in vivo antipyretic activity of the methanolic extracts of selected three Annona plant leaves.Methods: The acute oral toxicity determined by OECD class method and the in vivo antipyretic activity was determined by brewer's yeast inducedpyrexia method.Results: The results showed that the methanolic extract of leaves of Annona plants are non-toxic and possessed significant antipyretic effect whichmay be attributed to the presence of flavonoids and saponins in the extracts.Conclusion: This study provides evidences for the antipyretic activity of Annona squamosa, Annona reticulata and Annona muricata possess antipyreticactivity at the tested doses 100 and 200 mg/kg body weight without any side effects, which could partly contribute to its ethno medical use.Keywords: Annona squamosa L, Annona reticulata L, Annona muricata L, Antipyretic activity, Brewer's yeast
Multiaxial fatigue studies on carbon steel piping material of Indian PHWRs
The tests studies and analyses have been carried out in the area of “Multiaxial Fatigue” with an objective to improve the damage assessment methodologies and design rules. Nearly 50 numbers of fatigue tests were conducted on solid and tubular specimens of SA333Gr.6 material under pure axial, pure shear and combined axial-torsion in-phase/ out-of-phase loading combinations. A software has been developed for the evaluation of multiaxial fatigue damage for the analyses of tests data using different invariant fatigue models such as ASME Sec.III code procedures, von-Mises etc. The fatigue crack initiation life was predicted using the best fit axial fatigue life curve (without use of safety factors). These tests and their analyses have helped
in understanding the fatigue failure behavior of piping material under complex cyclic loadings where the principal directions rotate during a loading cycle. The crack initiation angles have also been measured by analyzing the image of the tested specimens. The measured crack angles will help in validation of the critical plane based models
Impact of elevated temperature on root traits and microbial interaction in cotton (Gossypium hirsutum L.) genotypes
Climate change mainly alters the plant phyllosphere and rhizosphere resource allocations. Compared with shoot parameters, there is less information about how roots, especially root system architecture (RSA) and their interactions with others, may respond to elevated temperature changes. These responses could greatly influence different species acquisition of resources and their competition with their neighbours. The main aim of this experiment was to evaluate the effects of ambient temperature (T1) and elevated temperature (+4oC) (T2) in Open-top chamber (OTC) on root traits and microbial interaction changes in cotton (Gossypium hirsutum L.). A pot experiment was conducted at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore, during 2020-2021 to investigate the root traits and microbial interactions. Cotton varieties, namely KC3, SVPR6, TSH325, TSH357 and TSH375 were screened at the seedling level for cellular thermo tolerance and further, at the root level, these selected varieties were studied against the elevated temperature condition for 10 days in OTC during the stage of flowering to boll development period along with control temperature condition. Root interactions' intensity and direction may fluctuate as a result of variations in RSA responses between species. Negative root interactions could become more intense under high temperature circumstances and species with bigger roots and greater early root growth had stronger competitive advantages. The present findings showed that elevated temperatures promote various microbial growths in the geothermal regions, enhancing the root angle and root length of cotton species. Among the genotypes, KC3 and SVPR6 performed better under elevated temperatures.
Effect of Temperature induction response on Cell viability, Cell Survivability, Malondialdehyde content and total soluble protein content of cotton (Gossypium hirsutum L.) genotypes
“Temperature Induction Response” (TIR) technique was employed to investigate the effect of temperature on popular 20 cotton (Gossypium hirsutum L.) genotypes in a laboratory experiment conducted at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore during 2020-2021. Identical sized ten days old cotton seedlings were selected and subjected to inductive temperature (gradual temperature raised from 28 to 40℃) for 4 h and non-inductive temperature (46℃ for 3 h, 47℃ for 3 h, 48℃ for 3 h and 48℃ for 4 h) for specific time duration. KC3 and SVPR6 recorded highest thermotolerance among the genotypes and TSH325 and TSH357 showed moderate thermotolerance while TSH375 and TSH383 were sensitive, in terms of seedling survival, cell viability, total soluble protein and malondialdehyde compared to remaining genotypes under non-inductive temperature
Effect of isospin dependent cross-section on fragment production in the collision of charge asymmetric nuclei
To understand the role of isospin effects on fragmentation due to the
collisions of charge asymmetric nuclei, we have performed a complete
systematical study using isospin dependent quantum molecular dynamics model.
Here simulations have been carried out for , where n
varies from 47 to 59 and for , where m varies from 14
to 23. Our study shows that isospin dependent cross-section shows its influence
on fragmentation in the collision of neutron rich nuclei
Salinity Measurements Collected by Fishermen Reveal a “River in the Sea” Flowing Along the Eastern Coast of India
Being the only tropical ocean bounded by a continent to the north, the Indian Ocean is home to the most powerful monsoon system on Earth. Monsoonal rains and winds induce huge river discharges and strong coastal currents in the northern Bay of Bengal. To date, the paucity of salinity data has prevented a thorough description of the spreading of this freshwater into the bay. The potential impact of the salinity on cyclones and regional climate in the Bay of Bengal is, however, a strong incentive for a better description of the water cycle in this region. Since May 2005, the National Institute of Oceanography conducts a program in which fishermen collect seawater samples in knee-deep water at eight stations along the Indian coastline every 5 days. Comparison with open-ocean samples shows that this cost-effective sampling strategy is representative of offshore salinity evolution. This new dataset reveals a salinity drop exceeding 10 g kg−1 in the northern part of the bay at the end of the summer monsoon. This freshening signal propagates southward in a narrow (~100 km wide) strip along the eastern coast of India, and reaches its southern tip after 2.5 months. Satellite-derived alongshore-current data shows that the southward propagation of this “river in the sea” is consistent with transport by seasonal coastal currents, while other processes are responsible for the ensuing erosion of this coastal freshening. This simple procedure of coastal seawater samples collection could further be used to monitor phytoplankton concentration, bacterial content, and isotopic composition of seawater along the Indian coastlin
Formation and weathering assessment of oil-suspended sediment aggregates through a laboratory investigation.
Formation of oil-suspended sediment aggregates (OSAs) is believed to be one of the natural cleaning processes in the marine environment. In this study, we have investigated the formation processes of OSAs under different mixing periods (continuous mixing and with the addition of sediments in between), oil-sediment ratios (1:1, 1:2 and 2:1) and crude oils (Arabian Light (AL), Kuwait (KW) and Murban (MB)). The results revealed that size of OSAs significantly increased (up to ≈ 1.41 mm) with the addition of sediments. Aggregates (total 36) were extracted for n-alkanes and polycyclic aromatic hydrocarbons to quantify and assess their weathering and toxic levels. The maximum n-alkane depletion was 84% (111-02), 94% (212-02) and 84% (321-02) and PAH depletion was ≈ 72% (111-02), 79% (212-02) and 81% (311-03) for the OSAs of AL, KW and MB crude oils, respectively, for the different samples considered, indicating that n-alkanes were depleted relatively higher than the PAHs. The highest depletion of both n-alkane and PAHs has occurred in OSAs of 10-h continuous mixing. The depletion of both n-alkane and PAHs reduced after the addition of sediments, however, escalated the growth of OSAs, resulting in bigger size OSAs. The concentration of PAHs of all 36 OSAs is greater than 5000 ng/g, indicating very high PAH pollution. Though the formation of OSAs helps in cleaning the spill sites, the carcinogenic threat to the marine ecosystem caused by these OSAs cannot be ignored.This study is funded by the Department of Science and Technology through Climate Change Programme to VS
4-Bromo-3-{N-[2-(3,4-dimethoxyphenyl)ethyl]-N-methylsulfamoyl}-5-methylbenzoic acid monohydrate
In the title compound, C19H22BrNO6S·H2O, the dihedral angle between the planes of the two benzene rings is 3.1 (1)°. These rings are stacked over one another with their centroids separated by 3.769 (2) Å, indicating weak π–π interactions. In the crystal structure, molecules are linked by O—H⋯O and O—H⋯(O,O) hydrogen bonds involving the water molecule, forming a two-dimensional network parallel to (001)
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