19 research outputs found

    Optical Spectroscopy of Type Ia Supernovae

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    We present 432 low-dispersion optical spectra of 32 Type Ia supernovae (SNe Ia) that also have well-calibrated light curves. The coverage ranges from 6 epochs to 36 epochs of spectroscopy. Most of the data were obtained with the 1.5m Tillinghast telescope at the F. L. Whipple Observatory with typical wavelength coverage of 3700-7400A and a resolution of ~7A. The earliest spectra are thirteen days before B-band maximum; two-thirds of the SNe were observed before maximum brightness. Coverage for some SNe continues almost to the nebular phase. The consistency of the method of observation and the technique of reduction makes this an ideal data set for studying the spectroscopic diversity of SNe Ia.Comment: Accepted for publication in the Astronomical Journal, 109 pages (including data table), 44 figures, full resolution figures at http://www.noao.edu/noao/staff/matheson/Iaspec.ps.g

    The Morphology of the Expanding Ejecta of V2491 Cygni (2008 N.2)

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    Determining the evolution of the ejecta morphology of novae provides valuable information on the shaping mechanisms in operation at early stages of the nova outburst. Understanding such mechanisms has implications for studies of shaping for example in proto-Planetary Nebulae. Here we perform morpho-kinematical studies of V2491 Cyg using spectral data to determine the likely structure of the ejecta and its relationship to the central system and shaping mechanisms. We use Shape to model different morphologies and retrieve their spectra. These synthetic spectra are compared with observed spectra to determine the most likely morphology giving rise to them, including system inclination and expansion velocity of the nova ejecta. We find the best fit remnant morphology to be that of polar blobs and an equatorial ring with an implied inclination of 8012+3^{+3}_{-12} degrees and an maximum expansion velocity of the polar blobs of 3100100+200^{+200}_{-100} km/s and for the equatorial ring 2700100+200^{+200}_{-100} km/s. This inclination would suggest that we should observe eclipses which will enable us to determine more precisely important parameters of the central binary. We also note that the amplitude of the outburst is more akin to the found in recurrent nova systems.Comment: 9 pages, 7 figures, accepted for publication in MNRA

    Incorporation of Labelled Amino Acid into Ova during Ovarian Development in the Silkworm, Bombyx mori L.

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    © 2019 Elsevier B.V. Helical turbulator has been adopted in this article, to enhance the convective flow within a pipe. Homogeneousmodel was carried out for nanomaterial modeling. The Reynolds number (Re) and width of turbulator (b) vary from 5000 to 15000 and 5 to 15mm, respectively. Copper oxide nanoparticles were considered as an additive in to pure carrier fluid to gain better thermal behavior. Furthermore, exergy loss distributions for different cases have been reported. Outputs indicate that disturbance of the boundary layer enhances with rise of b. Mixing of core nanofluid flow and boundary layer enhances with augment of width of turbulator

    A Systematic Study of Mid-Infrared Emission from Core-Collapse Supernovae with Spirits

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    The American Astronomical Society. All rights reserved.We present a systematic study of mid-infrared emission from 141 nearby supernovae (SNe) observed with Spitzer/IRAC as part of the ongoing SPIRITS survey. We detect 8 Type Ia and 36 core-collapse SNe. All Type Ia/Ibc SNe become undetectable within three years of explosion, whereas 22 ± 11% of Type II SNe continue to be detected. Five Type II SNe are detected even two decades after discovery (SN 1974E, 1979C, 1980K, 1986J, and 1993J). Warm dust luminosity, temperature, and a lower limit on mass are obtained by fitting the two IRAC bands, assuming an optically thin dust shell. We derive warm dust masses between 10-6 and 10-2 M o and dust color temperatures between 200 and 1280 K. This observed warm dust could be pre-existing or newly created, but in either case represents a lower limit to the dust mass because cooler dust may be present. We present three case studies of extreme SNe. SN 2011ja (II-P) was over-luminous ([4.5] = -15.6 mag) at 900 days post explosion with increasing hot dust mass, suggesting either an episode of dust formation or intensifying circumstellar material (CSM) interactions heating up pre-existing dust. SN 2014bi (II-P) showed a factor of 10 decrease in dust mass over one month, suggesting either dust destruction or reduced dust heating. The IR luminosity of SN 2014C (Ib) stayed constant over 800 days, possibly due to strong CSM interaction with an H-rich shell, which is rare among stripped-envelope SNe. The observations suggest that this CSM shell originated from an LBV-like eruption roughly 100 years pre-explosion. The observed diversity demonstrates the power of mid-IR observations of a large sample of SNe. © 2017

    The Eruption of the Candidate Young Star ASASSN-15qi

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    Outbursts on young stars are usually interpreted as accretion bursts caused by instabilities in the disk or the star-disk connection. However, some protostellar outbursts may not fit into this framework. In this paper, we analyze optical and near-infrared spectra and photometry to characterize the 2015 outburst of the probable young star ASASSN-15qi. The 3.5\sim 3.5 mag brightening in the VV band was sudden, with an unresolved rise time of less than one day. The outburst decayed exponentially by 1 mag for 6 days and then gradually back to the pre-outburst level after 200 days. The outburst is dominated by emission from 10,000\sim10,000 K gas. An explosive release of energy accelerated matter from the star in all directions, seen in a spectacular cool, spherical wind with a maximum velocity of 1000 km/s. The wind and hot gas both disappeared as the outburst faded and the source the source returned to its quiescent F-star spectrum. Nebulosity near the star brightened with a delay of 10-20 days. Fluorescent excitation of H2_2 is detected in emission from vibrational levels as high as v=11v=11, also with a possible time delay in flux increase. The mid-infrared spectral energy distribution does not indicate the presence of warm dust emission, although the optical photospheric absorption and CO overtone emission could be related to a gaseous disk. Archival photometry reveals a prior outburst in 1976. Although we speculate about possible causes for this outburst, none of the explanations are compelling

    Mioquimia orbicular y sulfato de glucosamina

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    Acceleration of solidification process by means of nanoparticles in an energy storage enclosure using numerical approach

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    In this article, simulations are performed to explore the feasibility of utilizing nanoparticle and sinusoidal cold inner cylinder to decrease time of solidification. Storage tank is full of NEPCM (CuO-water). The focus of current modeling is on the impacts of shape of cold wall and concentration of NEPCM on discharging rate. Simulation of the transient process was carried out employing FEM based Galerkin method. Decreasing amplitude of inner wall results in prolonging solidification while increasing N, results opposite outcome. Propagation rate of solid fraction enhances with augment of volume fraction of NEPCM

    Bioequivalence of a biosimilar enoxaparin sodium to Clexane® after single 100 mg subcutaneous dose: results of a randomized, double-blind, crossover study in healthy volunteers

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    Javier Martínez González, Mayte Monreal, Ignacio Ayani Almagia, Jordi Llaudó Garín, Lourdes Ochoa Díaz de Monasterioguren, Ibón Gutierro Adúriz R&D Department, Laboratorios Farmacéuticos Rovi S.A., Madrid, Spain Purpose: To demonstrate the pharmacokinetic/pharmacodynamic (PK/PD) equivalence of a biosimilar enoxaparin to the reference drug, and to assess its safety and tolerability in healthy volunteers. Patients and methods: A randomized, double-blind, crossover, 2-sequence, single-dose study was conducted in healthy volunteers of both sexes. Participants were sequentially and randomly administered single subcutaneous injections of enoxaparin 100 mg manufactured by Rovi (test; Madrid, Spain) and Clexane® (enoxaparin 100 mg manufactured by Sanofi, reference) separated by a 1-week washout period. The primary PK/PD variables were maximum activity (Amax) and area under the effect curve from time 0 to the last measured activity (T) (AUEC0–T) and AUEC from time 0 to infinity (AUEC0–inf) of anti-FXa activity, and Amax and AUEC0–T of anti-FIIa activity. Secondary variables were Amax and AUEC0–T, AUEC0–inf of tissue factor pathway inhibitor, and the ratio of AUEC0–T anti-FXa to anti-FIIa activity. Biosimilarity would be shown when the 95% CI of the ratio of geometric least squares means (95% CI RGLSMs) of primary PK/PD parameters fell within the standard range of bioequivalence, ie, 80%–125%.Results: The study sample consisted of 46 volunteers (33 males) aged 18–44 years and with body mass index ranging from 19.0 to 31.1 kg/m2. Three subjects did not complete the study. The curves of anti-FXa, anti-FIIa and tissue factor pathway inhibitor activities corresponding to administration of the test and reference products were comparable. The 95% CI RGLSMs of Amax, AUEC0–T and AUEC0–inf for anti-FXa activity were 94.6%–105.9%, 99.8%–108.0% and 100.0%–108.6% respectively; Amax and AUEC0–T for anti-FIIa activity were 94.7%–112.6% and 90.9%–117.9% respectively. In addition, the 95% CI RGLSMs of all secondary variables fell within the range 80%–125%. The incidence and types of adverse events after administration of the test and reference drugs were similar. Conclusion: The results conclusively showed that the enoxaparin manufactured by Rovi is equivalent to the reference enoxaparin in all primary and secondary PK/PD parameters, as required by the European Medicines Agency to grant marketing authorization to a biosimilar low molecular-weight heparin. Keywords: biosimilar, LMWH, pharmacodynamics, pharmacokinetics, anti-FXa, anti-FIIa, TFP
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