A Study on the Effectiveness of Bracing System for Lateral loading

An attempt has been made to study the reduction in responses of a structure under lateral loading due to the incorporation of a bracing system. In practice a building structure is subjected to eccentric loading due to the placement of different nonstructural elements within and above the structure. Due to the effect of eccentric loading a building normally experiences lateral as well as torsional displacement under seismic loading. Bracing system in any form increases the overall stiffness of the system and hence acts as a control mechanism for both lateral and torsional movement of the structure. In this study a single storey steel frame model is analyzed in a shake table for three different loading conditions namely frame without any extra mass, frame with a central mass and frame with an eccentric mass. A pair of X bracing system is then introduced to the structure and analyzed for the same three conditions. Comparisons are made for different responses namely lateral displacement, velocity, acceleration and torsional movement of the frame at roof level with and without bracing system. From the study it is clear that the bracing system is effective for reducing the lateral movement as well as the torsional effect to a great extent. Model study shows that a bracing system results in a reduction in the displacement at roof level up to about 80% as compared to that of an unbraced frame

A GBT Survey for HI 21 cm Absorption in the Disks and Halos of Low-Redshift Galaxies

We present an HI 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining data from the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. Our sample consists of 23 sightlines through 15 low-redshift foreground galaxy - background quasar pairs with impact parameters ranging from 1.7 kpc up to 86.7 kpc. We detected one absorber in the GBT survey from the foreground dwarf galaxy, GQ1042+0747, at an impact parameter of 1.7 kpc and another possible absorber in our follow-up Very Large Array (VLA) imaging of the nearby foreground galaxy, UGC 7408. Both of the absorbers are narrow (FWHM of 3.6 and 4.8 km/s), have sub Damped Lyman alpha column densities, and most likely originate in the disk gas of the foreground galaxies. We also detected H I emission from three foreground galaxies, including UGC 7408. Although our sample contains both blue and red galaxies, the two H I absorbers as well as the H I emissions are associated with blue galaxies. We discuss the physical conditions in the 21 cm absorbers and some drawbacks of the large GBT beam for this type of survey.Comment: 15 pages, 6 figures, 3 table

Seroprevalence of canine dirofilariosis, granulocytic anaplasmosis and lyme borreliosis of public health importance in dogs from India’s North East

Aim: Vector-borne infections namely dirofilariosis, ehrlichiosis, anaplasmosis and lyme borreliosis are being recognized as emerging and/or re-emerging problems in dogs and man due to rapid extension of zoogeographical ranges of many causative agents through international tourism and increase mobility of dogs at national and international level towards meeting the demand for companion animals in the present day society. Anticipating such situation, a serological study was conducted in dogs from North East India to estimate the prevalence of zoonotically important Dirofilaria immitis, Anaplasma phagocytophilum and Borrelia burgdorferi along with Ehrlichia canis. Materials and Methods: Serological study was carried out using enzyme immunoassay in commercial SNAP 4DX® test kit (Idexx Laboratories, USA). The study was conducted in 191 dogs comprising 82 pets, 57 stray and 52 working dogs owned by defence organizations. Results: The study revealed seroprevalence of mosquito-borne D. immitis (17.80%), tick-borne E. canis (22.51%) and A. phagocytophilum (4.71%) with an overall 41.88% prevalence of pathogens in single or co-infection. Serological evidence of tick-borne lyme borreliosis due to B. burgdorferi could not be established in dogs in the present study. Of the zoonotic species, highest prevalence of D. immitis was found in the stray dogs (22.80%) and that of A. phagocytophilum in pet dogs (6.09%). Conclusion: The results of the present serological study serve as baseline information on the prevalence of A. phagocytophilum in dogs reported for the first time in India and reaffirmation on the high prevalence of D. immitis and E. canis in the North East India

Acidity & Catalytic Activity of Modified Zeolite-X

554-55

The morphology and kinematics of the gaseous circumgalactic medium of Milky Way mass galaxies - II. Comparison of IllustrisTNG and Illustris simulation results

We have carried out a controlled comparison of the structural and kinematic properties of the circumgalactic medium (CGM) around Milky Way mass galaxies in the Illustris and IllustrisTNG simulations. Very striking differences are found. At z = 0, gas column density and temperature profiles at large radii (~100 kpc) correlate stronglywith disc gasmass fraction in Illustris, but not in TNG. The neutral gas at large radii is preferentially aligned in the plane of the disc in TNG, whereas it is much more isotropic in Illustris. The vertical coherence scale of the rotationally supported gas in the CGM is linked to the gas mass fraction of the galaxy in Illustris, but not in TNG. A tracer particle analysis allows us to show how these differences can be understood as a consequence of the different subgrid models of feedback in the two simulations. A study of spatially matched galaxies in the two simulations shows that in TNG, feedback by supernovae and active galactic nuclei (AGNs) helps to create an extended smooth reservoir of hot gas at high redshifts, which then cools to form a thin, rotationally supported disc at later times. In Illustris, AGNs dump heat in the form of hot gas bubbles that push diffuse material at large radii out of the halo. The disc is formed by accretion of colder, recycled material, and this results in more vertically extended gas distributions above and below the Galactic plane.We conclude that variations in the structure of gas around Milky Way mass galaxies are a sensitive probe of feedback physics in simulations and are worthy of more observational consideration in future