Luminosity-Distances of Iue Observed Active Galaxies

Active galaxies are the most luminous objects observed in the Universe and are believed to be powered by mass accretion processes taking place in the vicinity of the central Super massive black hole (M BH ≥ 108M sun ). However, the details of the power generation mechanisms are not understood well yet. In this paper, we are presenting a comparative study of luminosity-distance estimations for the complete sample of active galaxies observed by IUE satellite by different methods. IUE has made UV spectroscopic observations of nearly 400 active galaxies comprising mostly Seyfert 1 galaxies and quasars. We have chosen all the active galaxies observed by IUE satellite for the study of luminosity-distance with redshift. The luminosity-distances (D L ) have been calculated using the Hubbles law under non-relativistic and relativistic limits with H0 = 73 Km/sec/Mpc and Terrell (1979) also. We have found that all D L estimations are consistent with each other for z ≤ 1 and diverge for z ≥ 1. The results of cosmological calulator I and II are found to consistent with each other and higher by several factors over cosmological calculator IV and the predictions of the Hubble's law under relativistic case. We observe a kind bimodal distributions in D L for z ≤ 3.5

Ultraviolet Line-Continuum Properties of Seyfert 1 Galaxies and Quasars

Active galaxies are most luminous objects in the universe whose spectra are characterized by both permitted and forbidden emission line features. The spectra of Seyfert 1 galaxies and quasars contain strong and broad emission lines of wide ranging ionization potentials. The velocity widths of the lines range from a minimum of ˜ 500 km/s for narrow lines to a maximum of 20,000 km/sec for broad lines. The UV spectra of the active galaxies contain strong and broad emission lines such as Lyα, NV, SiIV, OIV], CIV, CIII] and MgII lines. The widths of the broad lines are attributed to the differential doppler shifts of the emission lines due to the bulk motions of individual clumpy gas clouds in the BLR region. We have anlysed UV spectra of Seyfert 1 galaxies and quasars from IUE satellite archival database to understand the nature of dependence of the emission line properties with the underlying UV continuum. We have undertaken line luminosity correlation studies for Lyα and CIV lines with their underlying UV continuum luminosity at 1125Å, 1425Å & 1625Å. The IUE archival spectra have been reduced for galactic reddening using the E(B-V) and NHI values published continuum luminosity has been observed at 1125Å, 1425Å & 1625Å. The Lyα line line has exhibited strongest linear correlation wavelengths while CIV line has shown at 1425Å and 2625Å wavelengths. These results are empirically consistent with the predictions of the general multi-component photo-ionization models suggesting that the central strong UV continuum has been reprocessed by the clumpy gas clouds of the broad emission region (BLR). A detailed account of the data reduction, UV flux measurement and the significance of line-luminosity correlations are discussed in this paper

Secondary arm coarsening and microsegregation in superalloy PWA-1480 single crystals: Effect of low gravity

Single crystal specimens of nickel base superalloy PWA-1480 were directionally solidified on ground and during low gravity (20 sec) and high gravity (90 sec) parabolic maneuver of KC-135 aircraft. Thermal profiles were measured during solidification by two in-situ thermocouples positioned along the sample length. The samples were quenched during either high or low gravity cycles so as to freeze the structures of the mushy zone developing under different gravity levels. Microsegregation was measured by examining the solutal profiles on several transverse cross-sections across primary dendrites along their length in the quenched mushy zone. Effect of gravity level on secondary arm coarsening kinetics and microsegregation have been investigated. The results indicate that there is no appreciable difference in the microsegregation and coarsening kinetics behavior in the specimens grown under high or low gravity. This suggests that short duration changes in gravity/levels (0.02 to 1.7 g) do not influence convection in the interdendritic region. Examination of the role of natural convection, in the melt near the primary dendrite tips, on secondary arm spacings requires low gravity periods longer than presently available on KC-135. Secondary arm coarsening kinetics show a reasonable fit with the predictions from a simple analytical model proposed by Kirkwood for a binary alloy

Production status of GaAs/Ge solar cells and panels

GaAs/Ge solar cells with lot average efficiencies in excess of 18 percent were produced by MOCVD growth techniques. A description of the cell, its performance and the production facility are discussed. Production GaAs/Ge cells of this type were recently assembled into circuits and bonded to aluminum honeycomb panels to be used as the solar array for the British UOSAT-F program

Fishery and bionomics of sciaenids of South Kanara

Sciaenids, popularly known is jew fish, croakers or drums are one of the commercially important groups of marine fishes of India. They rank very high in abundance forming on an average, 7,04 % of the tora-f{.p1arine fish catch of the country (1974-76)

Evaluation of antifungal activity of seaweed extract (Turbinaria conoides) against Fusarium oxysporum

The purpose of the study was to determine the anti fungal activity of seaweed (Turbinaria conoides) extract against root rot pathogen Fusarium oxysporum. Seaweed extract was prepared from the species T. conoides collected from Rameswaram coastal area of Tamil Nadu during December was used for this study. Different concentrations of the extract viz., 5 %, 10 %, 15 % and 20 % was evaluated for their antifungal activity against F. oxysporum using poisoned food technique along with control and carbendazim (0.2 %) as check. No mycelial growth (0 cm) was observed in 15 % and 20 % sea weed extract weed extract treated plates even after 6 days ofincubation. Though the visible inhibition of mycelial growth was noticed in all the concentrations, the increased concentration of 15 and 20 % had shown 100 % inhibition. So, the lower concentration of 15 % can be best in controlling the F. oxysporum fungi. GC-MS analysis of seaweed extract showing the presence of several antimicrobial compounds in seaweeds may be the reason for such inhibition

Optimization of Drilling Process Parameters on Die Steel (H13) using Carbide Coated Drill by Design of Experiment Concept

This experimental work presents the optimization of process parameter of surface roughness with using coated carbide drill on H13 steel. Taguchi design of experiments was implemented for executing the process parameter of Drilling process on H13 steel plates. The drilling parameters including 2 Factors such as spindle speed (rpm) and feed rate (mm/min) are optimized using response performance characteristic of surface roughness of H13 die steel plates.H13 steel play an important role in many applications such as Shaft, axle, gears and fasteners due to their strength to weight ratio. The process parameters of spindle speed and feed rate are influenced by machining accuracy during drilling process. The main objectives of experimental works have been identified by lower roughness during drilling process of H13 steel plates. Orthogonal array (L16) of Taguchi Design of experiments and Analysis of Variance (ANOVA) are utilized to analyze the effect of drilling parameters on Quality of drilled holes. The result of experiments indicate is a dominating parameter of surface roughness of H 13 steel plates in Drilling process

Synthesis of phenylacetates using aluminium-exchanged montmorillonite clay catalyst

Liquid phase esterification of phenylacetic acid with phenol and substituted phenols has been investigated over montmorillonite clay exchanged with H + - Al 3+ - and aluminium polyhydroxy oligomer cations. Among the catalysts studied, Al 3+ - montmorillonite dried at 100°C showed 67 conversion, while the same catalyst dried at 200deg;C showed reduced conversion of 36. Al 3+ - montmorillonite dried at 400°C and montmorillonite exchanged with aluminium polyhydroxy oligomer cations dried at 100°C and calcined at 500°C failed to bring about the reaction. Effects of mole ratio of reactants, reaction period and catalyst amount on yield of the ester and catalyst regeneration are also investigated. Esterification of phenylacetic acid with phenol, cresols, nitrophenols and resorcinol has been carried out in the presence of montmorillonite clay exchanged with H +-ions, Al 3+-ions and polyhydroxy oligomer cations of Al. Na +-montmorillonite (raw clay) was inactive, H +- and Al 3+-montmorillonites, dried at 100°C, showed 52 and 67 conversions to ester, respectively, upon refluxing the phenylacetic acid (20 mmol) and p-cresol (40 mmol) for 6 h. While Al 3+- montmorillonite dried at 200°C showed a conversion of 36 the same catalyst when dried at 400°C showed no conversion. Montmorillonite exchanged with aluminium polyhydroxy oligomers dried at 100°C and calcined at 500°C to get pillared clay (d 0 0 1=17.5 à ) failed to bring about the esterification. Effect of concentration of reactants, amount of catalyst and the reaction time on the yield of p-cresyl phenylacetate has been investigated. The esterification of phenylacetic acid with phenol and substituted phenols like m-cresol, o-cresol, p-nitro phenol and o-nitro phenol showed reduced yield due to steric factors. The activity of the clay catalyst after regeneration has also been studied. © 2004 Published by Elsevier B.V

Reproductive biology of Sciaenid fish, Johnieops osseus (Day), from the South Kanara coast

Though some informalion is available regarding the breeding habits and early life histories of sciaenids'-s detailed studies on reproductive biology are lacking. The present paper deals with the reproductive biology of Johtlieops osseus, the dominant species of the sciaenids captured off South Kanara Coast