Thermonuclear burst physics with RXTE

Recently we have made measurements of thermonuclear burst energetics and recurrence times which are unprecedented in their precision, largely thanks to the sensitivity of the Rossi X-ray Timing Explorer. In the "Clocked Burster", GS 1826-24, hydrogen burns during the burst via the rapid-proton (rp) process, which has received particular attention in recent years through theoretical and modelling studies. The burst energies and the measured variation of alpha (the ratio of persistent to burst flux) with accretion rate strongly suggests solar metallicity in the neutron star atmosphere, although this is not consistent with the corresponding variation of the recurrence time. Possible explanations include extra heating between the bursts, or a change in the fraction of the neutron star over which accretion takes place. I also present results from 4U 1746-37, which exhibits regular burst trains which are interrupted by "out of phase" bursts.Comment: 4 pages, 2 figures, AIP conference proceedings format. To appear in the proceedings of the "X-ray Timing 2003: Rossi and Beyond" meeting held in Cambridge, MA, November, 200

Instability of Quark Matter Core in a Compact Newborn Neutron Star With Moderately Strong Magnetic Field

It is explicitly shown that if phase transition occurs at the core of a newborn neutron star with moderately strong magnetic field strength, which populates only the electron's Landau levels, then in the $\beta$-equilibrium condition, the quark core is energetically much more unstable than the neutron matter of identical physical condition.Comment: Six pages REVTEX file, one .eps file (included

Characterizations of the diurnal shapes of OI 630.0 nm dayglow intensity variations: inferences

International audienceMeasurements of OI 630.0 nm thermospheric dayglow emission by means of the Dayglow Photometer (DGP) at Mt. Abu (24.6° N, 73.7° E, dip lat 19.09° N), a station under the crest of Equatorial Ionization Anomaly (EIA), reveal day-to-day changes in the shapes of the diurnal profiles of dayglow intensity variations. These shapes have been characterized using the magnetometer data from equatorial and low-latitude stations. Substantial changes have been noticed in the shapes of the dayglow intensity variations between 10:00?15:00 IST (Indian Standard Time) during the days when normal and counter electrojet events are present over the equator. It is found that the width (the time span corresponding to 0.8 times the maximum dayglow intensity) of the diurnal profile has a linear relationship with the integrated electrojet strength. Occasional deviation from this linear relationship is attributed to the presence of substantial mean meridional wind

Equatorial Spread F structures and associated airglow intensity variations observed over Gadanki

Co-ordinated campaigns have been conducted from Gadanki (13.5° N, 79.2° E, dip lat 6.4° N) by operating simultaneously the Indian MST radar in ionospheric coherent backscatter mode and by monitoring thermosphere airglow line emissions (630.0 nm and 777.4 nm) using a narrow band multi-wavelength scanning photometer during January-March for the past five years (2003–2007) and also during April 2006, as a special campaign. Simultaneous radar and optical observations reveal optical signatures corresponding to a variety of equatorial spread F (ESF) structures. The optical signatures corresponding to ESF structures with wave-like bottomside modulations with plasma plumes, confined bottomside flat and wavelike structures, vertically extended plume structure in the absence of bottomside structure apart from the classical plasma depletions and enhancements are obtained during these campaigns. The plasma depletions and enhancements were identified using optical measurements. In addition, estimations of zonal wavelength of the bottomside structures and the inference of shears in the zonal plasma drift in the presence of confined structures, were carried out using bi-directional airglow measurements. Furthermore, it is found that the vertical columnar intensity of OI 630.0 nm airglow exceeded the slanted columnar intensity in the presence of large bottomside structure. The need for the appropriate physical mechanisms for some of the ESF structures and their characterizations with optical observations are discussed

Biodegradation of organo-metallic pollutants in distillery wastewater employing bioaugmentation process

This objective of this work was to study the potential of a constructed bacterial consortium (comprising strains of Stenotrophomonas maltophilia, Bacillus cereus, and Bacillus thuringiensis) to treat distillery wastewater via the bioaugmentation process. The discharged wastewater showed elevated total ammonium nitrogen (195.0 ± 1.24 mg L-1), total dissolved solids (25980.6 ± 8.09 mg L-1), chemical oxygen demand (20534.5 ± 3.12 mg L-1), and biological oxygen demand (20534.5 ± 3.12 mg L-1). High concentration of heavy metals, phenolic and organo-metallic compounds were also detected. Results showed that growing the bacterial consortium in the distillery wastewater at 37 ºC supplemented with 1% glucose achieved the best colour reduction (up to 90 %) in 144 h. The physico-chemical quality of the treated wastewater also improved by 50-70 %. Furthermore, many of the major organic pollutants present in the distillery wastewater were degraded by the constructed consortium to below detection limit via active biotransformation and biodegradation. Heavy metals were biosorbed by the bacterial consortium, and the ligninolytic enzymes such as Lip and MnP played an important role in the degradation of the organo-metallic pollutants. The constructed bacterial consortia therefore offered a sustainable and effective solution to treat distiller wastewater

Proximate composition, calcium and phosphorus contents of five varieties of deep sea fishes of Andhra coast

Five varieties of deep sea fishes Psenes Indicus, Decapterus day/, Priacanthus sp. Centrolophus niger and deep sea pink prawn (Solenocera hextii) were collected from the deep-sea fishing vessels of Fishery Survey of India from VIsakhapatnam base. These were analysed for their proximate composition, calcium and phosphorus contents in the edible muscle portions. Sensory evaluation of the edible muscle of these fishes was carried out and found to be tasty and acceptable. The fat content is very high in these deep-sea fishes and they deserve consideration while developing suitable processing techniques