Biopolymer Based Nanomaterials as Potential Biosorbents for Lead Ions

The objectives of the present work included synthesis of nanoparticles of calcium crosslinked alginate by emulsion crosslinking method and their characterization by techniques such as FTIR, TEM and XRD. In order to study the effect of various factors like adsorbent dose, initial metal ion concentration, pH and temperature on the removal of lead ions from water using nanoparticles of alginate, a series of batch sorption experiments were conducted. The obtained results were analyzed by Langmuir and Freundlich isotherm models and it was found that the adsorption of lead more precisely follows Freundlich adsorption isotherm. The results were also analyzed through various kinetic models like Lagergreen pseudo-first order kinetics, the pseudo-second order kinetics, and intraparticle diffusion model. Adsorption of Pb ions from aqueous solutions was found to be best described by pseudo second order Lagergreen equation. It was also found that intra particle transport was not the rate limiting step. The removal of Pb ions was found to be more than 90 percent. The metal ion removal capacity of the nanoparticles was found to depend on the chemical composition of the adsorbent, concentration of the metal ion solution, pH and temperature of the medium and speed of the suspension. Keywords: lead, alginate, nanoparticles, adsorption, emulsion cross linking

Preparation and Characterization of Poly (2-hydroxyethyl methacrylate) (PHEMA) Nanoparticles with Possible Applications in Controlled Drug Delivery

The present work describes preparation, structural and morphological characterization of PHEMA nanoparticles. It is found that the nanoparticles are having size up to 100 nm and are almost identical in shape. The small size of nanoparticles makes them a suitable candidate for biomedical and pharmaceutical applications especially to controlled drug delivery field. Key words : Nanoparticals, PHEM, TEM, SE

Effect of participatory women's groups facilitated by Accredited Social Health Activists on birth outcomes in rural eastern India: A cluster-randomised controlled trial

Background: A quarter of the world's neonatal deaths and 15% of maternal deaths happen in India. Few community-based strategies to improve maternal and newborn health have been tested through the country's government-approved Accredited Social Health Activists (ASHAs). We aimed to test the effect of participatory women's groups facilitated by ASHAs on birth outcomes, including neonatal mortality. Methods: In this cluster-randomised controlled trial of a community interve

Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society