Comparative studies of removal of hazardous dyes, methylene blue (MB) and malachite green (MG) from solutions by low cost activated carbon

The removal of two hazardous dyes, MB and MG newly synthesized economic activated carbon. The adsorbent was synthesized from an agro waste material. The activated carbon has been characterized by XRD, FTIR, SEM, and surface area. A comparative study of the removal of selected dyes was reported. The process of removal for both the dyes is optimized for important parameters. It has been observed that removal of the dyes is maximum in alkaline range of pH. Both for MB and MG, the removal is controlled by first order kinetics. Mass transfer studies for both the dyes have been reported and the values of coefficient of mass transfer are found to be 2.25×10-5 cm/s and 1.92 cm/s respectively at 30°C. The rates of transfer of dyes onto the adsorbent surface were significant both the cases. The process of removal is endothermic and in both the cases higher temperature favoured the removal. Equilibrium data fitted Freundlich adsorption isotherm and the values of constants are found to be 0.59 and 3.01 mg/g for the removal of selected dyes. The results show suitability of the synthesized material for both the systems and can serve as baseline data for dyes removal

Comparative studies of removal of hazardous dyes, methylene blue (MB) and malachite green (MG) from solutions by low cost activated carbon

297-304The removal of two hazardous dyes, MB and MG newly synthesized economic activated carbon. The adsorbent was synthesized from an agro waste material. The activated carbon has been characterized by XRD, FTIR, SEM, and surface area. A comparative study of the removal of selected dyes was reported. The process of removal for both the dyes is optimized for important parameters. It has been observed that removal of the dyes is maximum in alkaline range of pH. Both for MB and MG, the removal is controlled by first order kinetics. Mass transfer studies for both the dyes have been reported and the values of coefficient of mass transfer are found to be 2.25×10-5 cm/s and 1.92 cm/s respectively at 30°C. The rates of transfer of dyes onto the adsorbent surface were significant both the cases. The process of removal is endothermic and in both the cases higher temperature favoured the removal. Equilibrium data fitted Freundlich adsorption isotherm and the values of constants are found to be 0.59 and 3.01 mg/g for the removal of selected dyes. The results show suitability of the synthesized material for both the systems and can serve as baseline data for dyes removal

Sorption characteristics of economically viable silicate sorbents for sequestration of lead ions from aqueous solutions

The adsorption of Pb2+ from aqueous solutions by sorbents based on calcium silicates, obtained in multicomponent systems CaCl2-Na2SiO3-H2O (sorbent I) and CaSO4·2H2O-SiO2·nH2O-KOH-H2O (sorbent II), was studied. Surface area of the two sorbents was found to be 100 and 40 m2/g respectively. The sorption capacities of the adsorbent materials were found to be 3.6 l/mmol and 8.4 l/mmol respectively. Characterization of the sorbent materials was carried out. The equilibrium data was fitted in Langmuir's isotherm and the adsorption capacity of the adsorbent materials was determined. The distribution coefficients at Pb2+ ions for the sorbents were determined at different ratios of solid and liquid phases

Description of Digestive Tract of Notonecta glauca Linn., the Indian Backswimmer

The backswimmer, Notonecta glauca Linnaeus for the morphological and bioecological investigations were collected during, the months of July to November from various ponds, ditches, and canals of Mathura and its nearby areas. These bugs were easily recognised due to their oblong, convex body; large eye; short four jointed antennae; four joined rostrum; large triangular scutellum; anterior legs inserted at the posterior margin of the pronotum; moderate long pronotum; last joint of antennae being must shorter than the penultimate one and posterior tarsi being without unguiculi. These insects are commonly known as water boatman and backswimmer as they swim on their backs with the help of their long oar-like hind legs. They are extremely predaceous and are very common around the edges of freshwater reservoirs such as ponds, lakes, and streams throughout India and the way be easily taken with a net. In the present study, a detailed description of the digestive tract of the aforesaid insect has been noted

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ethanol steam reforming with Co0 (111) for hydrogen and carbon nanofilament generation

The cobalt metal catalysts are highly active at low temperature ESR. In this study, ESR was studied over barren Co metal (Co0) from oxalate precursor without any pre-reduction to find out its role in hydrogen and carbon nano-filament generation. The ethanol conversion was found to be 100% with 96.5% hydrogen selectivity at 723K. The time on stream (TOS) study has shown stability up to 19h for Co catalyst. The diameter of Co-carbon nanofilament was calculated and found to be typically in the range of 70â80ânm by the TEM image analysis of spent catalyst. The SEM with EDS analysis revealed that Co0 state was found in between the carbon nanofilament as well as at the tip of carbon nanofilament. The obtained Co-C nanofilament displayed an adsorption capacity of 552âmg/g at optimum parameter of pHâ=â2, contact timeâ=â60 minute, concentrationâ=â30âppm, dose = 0.05g for Orange G dye removal without any chemical or physical treatment. This approach has shown significant results in terms of hydrogen generation and method of Co carbon nanofilament for further utilization in different prospects. Keywords: Catalyst deactivation, Characterization, ESR, Hydrogen productio