Associated HI absorption in the z=3.4 radio galaxy B2 0902+343 observed with the GMRT

We have made observations of the associated HI absorption of a high redshift radio galaxy 0902+34 at z=3.395 with the Giant Meterwave Radio Telescope in the $323\pm1$ MHz band. We find a narrow absorption line with a flux density of 11.5 mJy at a redshift of 3.397 consistent with that observed by Uson et al. (1991), Briggs et al. (1993) and de Bruyn (1996).A weak broad absorption feature reported by de Bruyn (1996) has not been detected in our observations. We also place an upper limit of 4 mJy (2 $\sigma$) on emission line strength at the position where Uson et al. (1991) claimed to have found a narrow emission line.Comment: To appear in Journal of Astronomy and Astrophysic

The Ooty synthesis radio telescope: first results

A 4-km synthesis radio telescope has recently been commissioned at Ootacamund, India for operation at 327 MHz. It consists of the Ooty Radio Telescope (530 m × 30 m) and 7 small antennas which are distributed over an area of about 4 km × 2 km. It has a coverage of about ± 40° in declination δ. The beam-width is about 40 arcsec × 90 arcsec at δ = 0° and about 40 arcsec × 50 arcsec at δ = 40°. The sensitivity attained for a 5:1 signal-to-noise ratio is about 15 m Jy after a 10-hour integration. The observational programmes undertaken and some of the results obtained recently are summarized. The radio halo around the edge-on spiral NGC 4631 is found to have a larger scale-height at 327 MHz than is known at higher frequencies. Mapping of interesting radio galaxies at 327 MHz is being carried out; preliminary results for 0511-305 (~2 Mpc) and 1333-337 (~750 kpc) are summarized. The very-steep-spectrum radio source in the Abell cluster A85 is found to be resolved; since it has no obvious optical counterpart, it is conceivable that it is a remnant of past activity of a galaxy that has drifted away in about 109 years

An observational constraint on the existence of proto-superclusters at z = 3.3

Observations have been conducted using the Ooty Radio Telescope in order to place constraints on the evolutionary scenario leading to the formation of the present day superclusters. The experiment attempted to detect 21 cm emission from massive neutral hydrogen condensates at a redshift of z = 3.3. In an Einstein de-Sitter universe with baryon density Ω = 0.05, about ten condensates were expected in the volume surveyed if superclusters, having H I masses ≃5 × 1015 M☉, were the first objects to separate out of the Hubble expansion. The sensitivity of our experiment rules out the existence of these condensates at z = 3.3 unless their lifetimes are less than one-tenth the dispersion in their epoch of formation or the proto-superclusters subtend angles greater than 6 arcmin. The result indicates that superclusters form at z > 3.3 if indeed they were the first objects to condense out of the Hubble flow

A simple image forming technique suitable for multifrequency observations of solar radio bursts

A simple image forming system using a multielement interferometer for obtaining rapid pictures of solar radio bursts is described. A dispersive transmission line is used to feed the elements in series through directional couplers. Truly instantaneous pictures of solar activity can be obtained by placing a number of narrow frequency filters at the end of the I. F. amplifier in the main receiver, located at one end of the array. The two dimensional extension of this principle is examined in some detail. Multibeaming in the two arrays of a crossed grating interferometer can be combined with fast phase-scanning in one of the arrays to produce rapid pencil beam pictures. If log-periodic antennas are used, observations can even be made at widely different frequencies simultaneously. For illustration, some important parameters for simultaneous observations at 60, 90 and 120 MHz are estimated for an interferometer assumed to be located at a latitude of 30° N. The main advantage of the proposed system is that high-resolution rapid pictures of radio bursts can be obtained simultaneously at a number of frequencies with modest effort

The Relation of Pilot Plants to Full Scale Operation

The author's chief interest in pilot plants is as a means of practical instruction. At the Banaras Hindu University a number of pilot plants have been installed so as to impart some practical Idea of metallurgical processes to final year students. These pilot plants include a sintering plant, several small size cupolas, an LD converter, a basic lined side blown converter, indirect arc furnace & high frequency electric furnaces. The latest addition to this range of pilot plants is a small scalp Edwards vacuum melting unit. In addition to their use for instructional purposes, it is hoped, as candidates present themselves, that these plants will be more fully employed in post- graduate res-earch, which it is felt will be of considerable importance to the development of the iron & steel industry in India. Post-graduate research, which it is felt will be of consi-derable importance to the development of the iron and steel industry in India. Post-graduate work of this nature must play an important role in the provision of thoroughly trained personnel for the rapidly growing industry in India

A study of feto-maternal outcome of jaundice in pregnancy

Background: Jaundice in pregnancy complicates 3-5% of cases and carries a grave prognosis. The purpose of the study was to assess the epidemiology, magnitude, causes and the maternal and fetal outcome of pregnancies complicated by jaundice.Methods: The maternal and fetal outcomes of 101 cases of jaundice in pregnancy were reviewed retrospectively from July 2013-June 2016.Results: The incidence of jaundice in pregnancy was 2.32%. Primigravidas constituted 46.53%. Women aged 20-30 years constituted 86.13%. Unbooked cases included 60.39%. Serum bilirubin was >10 mg/dl at admission in 1.98%. Out of the 101 women, 4 remained undelivered. Labor was spontaneous in 53.52%, vaginal delivery in 55.67%. However, 38.63% newborns required NICU care.  Perinatal mortality was 8.91% (3.96% stillbirths and 4.95% early neonatal deaths. The causes for jaundice were viral hepatitis (30.69%), HELLP syndrome (30.69%), intrahepatic cholestasis (15.84%), acute fatty liver of pregnancy (13.86%) and the rest in combination constituted 8.91%. Maternal mortality was 3 in 101. The various maternal complications were DIC (44.55%), septicemia (10.89%), ARDS (7.92%), acute renal failure (8.91%) and MODS (3.96%). ICU was needed in 14.85% of mothers and blood component therapy in 70.29% cases. All deaths were within 3 weeks of admission.Conclusions: This study emphasizes the need for essential antenatal care at domiciliary and peripheral levels. Early detection and treatment can prevent most of the complications

The Creation of Defects with Core Condensation

Defects in superfluid 3He, high-Tc superconductors, QCD colour superfluids and cosmic vortons can possess (anti)ferromagnetic cores, and their generalisations. In each case there is a second order parameter whose value is zero in the bulk which does not vanish in the core. We examine the production of defects in the simplest 1+1 dimensional scalar theory in which a second order parameter can take non-zero values in a defect core. We study in detail the effects of core condensation on the defect production mechanism.Comment: 9 pages, 7 figures, small corrections, 2 references added, final version to be published in PR

Environmental, developmental, and genetic factors controlling root system architecture

A better understanding of the development and architecture of roots is essential to develop strategies to increase crop yield and optimize agricultural land use. Roots control nutrient and water uptake, provide anchoring and mechanical support and can serve as important storage organs. Root growth and development is under tight genetic control and modulated by developmental cues including plant hormones and the environment. This review focuses on root architecture and its diversity and the role of environment, nutrient, and water as well as plant hormones and their interactions in shaping root architecture