Abundance and Occurrence of Phosphate Solubilizing Bacteria and Phosphatase in Sediment of Hooghly Estuary, North East Coast of Bay of Bengal, India

The abundance and occurrence of a special group of bacteria, capable of solubilizing or mobilizing insoluble phosphates were studied in estuarine environment, especially in sediments. The possible role of various factors of the sediments in maintaining the phosphate availability in the overlying water was described. The phosphatase activity was recorded in all samples irrespective of salinity variations. Total number of bacteria showed higher value in lower salinity. The total phosphate content in soil showed positive correlation with the phosphatase activity ( r = 0.890; P-Value = 0.000; n-=15). Clayey sediment contents more phosphate solubilizing bacteria and phosphatase than sandy sediment in a tropical estuarine region of River Hooghly

Laser surface nitriding of Ti-6Al-4V for bio-implant application

The present study aims at enhancing the biocompatibility of Ti-6Al-4V by laser surface nitriding. Laser surface nitriding has been carried out by melting of sand blasted Ti-6Al-4V substrate using a high power continuous wave DIODE laser with nitrogen as shrouding environment (at a pressure of 5l/min). Following laser treatment, a detailed characterization of the surface has been conducted. Microhardness and biocompatibility have been evaluated. Laser surface nitriding led to formation of dendrites of TiN on the surface. The microhardness is improved to 900- 950 VHN (in laser surface nitriding) as compared to 260 VHN of as-received substrate. Biocompatibility behavior showed a better cell viability in laser surface nitrided Ti-6Al-4V sample as compared to as-received one

Star-forming site RAFGL 5085: Is a perfect candidate of hub-filament system ?

To investigate the star formation process, we present a multi-wavelength study of a massive star-forming site RAFGL 5085, which has been associated with the molecular outflow, HII region, and near-infrared cluster. The continuum images at 12, 250, 350, and 500 $\mu$m show a central region (having M$_{\rm clump}$ $\sim$225 M$_{\odot}$) surrounded by five parsec-scale filaments, revealing a hub-filament system (HFS). In the {\it Herschel} column density ($N({{\rm{H}}}_{2})$) map, filaments are identified with higher aspect ratios (length/diameter) and lower $N({{\rm{H}}}_{2})$ values ($\sim$0.1--2.4 $\times$10$^{21}$ cm$^{-2}$), while the central hub is found with a lower aspect ratio and higher $N({{\rm{H}}}_{2})$ values ($\sim$3.5--7.0 $\times$10$^{21}$ cm$^{-2}$). The central hub displays a temperature range of [19, 22.5]~K in the {\it Herschel} temperature map, and is observed with signatures of star formation (including radio continuum emission). The JCMT $^{13}$CO(J= 3--2) line data confirm the presence of the HFS and its hub is traced with supersonic and non-thermal motions having higher Mach number and lower thermal to non-thermal pressure ratio. In the $^{13}$CO position-velocity diagrams, velocity gradients along the filaments toward the HFS appear to be observed, suggesting the gas flow in the RAFGL 5085 HFS and the applicability of the clump-fed scenario.Comment: 15 pages, 8 figures; Accepted for publication in Journal of Astrophysics and Astronomy (JOAA

Towards equation of state of dark energy from quasar monitoring: reverberation strategy

Context. High-redshift quasars can be used to constrain the equation of state of dark energy. They can serve as a complementary tool to supernovae Type Ia, especially at z > 1

Evaluation of hepatoprotective and antioxidant activity of Ichnocarpus frutescens (Linn.) R.Br. on paracetamol-induced hepatotoxicity in rats

Purpose: The entire plant including the flowers, of Ichnocarpus frutescens R.Br. (Apocynaceae) has been used for the treatment of cancer, skin infections, diabetes and liver disorder. The present study is aimed at evaluating the hepatoprotective effect of chloroform and methanol extract (CEIF and MEIF) of whole plant of I. frutescens (Linns) by paracetamol-induced liver damage in rats. Methods: The chloroform and methanolic extracts of I. frutescens (CEIF and MEIF) were studied for their hepatoprotective and antioxidant effects on paracetamol (750mg/kg) induced acute liver damage on Wistar albino rats. The degree of protection was measured by using biochemical parameters such as serum glutamate oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), bilirubin and total protein. Further, the effects of both extracts on lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were estimated. Results: CEIF and MEIF at a dose level of 250mg/kg and 500mg/kg produce significant (

Laser surface treatment of Ti-6Al-4V for bio-implant application

The present study aims at enhancing the wear resistance of Ti-6Al-4V by laser surface melting and nitriding and subsequently, studying the influence of laser surface treatment on the corrosion resistance in a simulated body fluid and also the bio-compatibility. The laser surface treatment is carried out using a high power continuous wave diode laser with argon and nitrogen as shrouding gas. Laser surface melting leads to an increased volume fraction of acicular martensite and a decreased volume fraction of the β phase in the microstructure. Laser surface nitriding leads to the formation of titanium nitride dendrites. The micro-hardness could be improved up to a maximum of 450 Hv in laser surface melting and 900-950 Hv in the case of laser surface nitriding as compared to 260 Hv of the as-received substrate. Surface melting increases the corrosion potential (Ecorr) and primary potential for pit formation (Epp1) significantly as compared to the as-received Ti-6Al-4V. However, when processed under similar conditions, surface nitriding shifts Ecorr marginally in the more noble direction, and increased Epp1 as compared to Ti-6Al-4V. The biocompatibility behaviour shows a superior cell viability on surface nitriding and an inferior cell viability on surface melting as compared to the as-received Ti-6Al-4V

IC 5146 dark Streamer: is a first reliable candidate of edge collapse, hub-filament systems, and intertwined sub-filaments?

The paper presents an analysis of multi-wavelength data of a nearby star-forming site IC 5146 dark Streamer (d $\sim$600 pc), which has been treated as a single and long filament, fl. Two hub-filament systems (HFSs) are known toward the eastern and the western ends of fl. Earlier published results favor the simultaneous evidence of HFSs and the end-dominated collapse (EDC) in fl. Herschel column density map (resolution $\sim$13$''$.5) reveals two intertwined sub-filaments (i.e., fl-A and fl-B) toward fl, displaying a nearly double helix-like structure. This picture is also supported by the C$^{18}$O(3-2) emission. The scenario "fray and fragment" may explain the origin of intertwined sub-filaments. In the direction of fl, two cloud components around 2 and 4 km s$^{-1}$ are depicted using the $^{13}$CO(1-0) and C$^{18}$O(1-0) emission, and are connected in velocity space. The HFSs are spatially found at the overlapping areas of these cloud components and can be explained by the cloud-cloud collision scenario. Non-thermal gas motion in fl with larger Mach number is found. The magnetic field position angle measured from the filament's long axis shows a linear trend along the filament. This signature is confirmed in the other nearby EDC filaments, presenting a more quantitative confirmation of the EDC scenario. Based on our observational outcomes, we witness multiple processes operational in IC 5146 Streamer. Overall, the Streamer can be recognized as the first reliable candidate of edge collapse, HFSs, and intertwined sub-filaments together.Comment: 22 pages, 11 figures, Accepted for publication in The Astrophysical Journa

Large-scale magnetic fields from inflation due to a CPTCPT-even Chern-Simons-like term with Kalb-Ramond and scalar fields

We investigate the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the $CPT$-even dimension-six Chern-Simons-like effective interaction with a fermion current by taking account of the dynamical Kalb-Ramond and scalar fields in inflationary cosmology. It is explicitly demonstrated that the magnetic fields on 1Mpc scale with the field strength of $\sim 10^{-9}$G at the present time can be induced.Comment: 18 pages, 6 figures, version accepted for publication in Eur. Phys. J.

A review on conversion of triglycerides to on-specification diesel fuels without additional inputs

Dependence on fossil fuels for global energy supply has continued to generate concerns about climate change and sustainable development. It has motivated the search for carbon-neutral alternative resources for the production of transportation fuels to replace crude oil. Although biodiesels have recently emerged as a close substitute to petrol diesel, their use in compression ignition engines designed to run on petro-diesel fuels are linked to adverse effects on the engines' performance and life span. This informed efforts at upgrading biodiesel or direct conversion of triglycerides to hydrocarbon mixtures that are identical or similar to that of petro-diesel through hydrodeoxygenation. Moreover, it seems that commercial methods for the conversion of triglycerides to diesel fuels depends on inputs (methanol and hydrogen) derived from fossil fuels. However, it will be desirable to do so without inputs from fossil fuels. Hence, reaction paths for direct conversion of triglycerides to on-specification hydrocarbons fuels without hydrogen gas input are discussed and suggested strategies are in cognisance of green chemistry principles