25 research outputs found

    E-learning: A new way of Library and Information Science Education through Distance Mode

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    This study explored that the e-learning mechanism is required to provide for quality of Library and Information Science education at university level through the distance learning. This paper is divided into three sections. The first section deals with the LIS education in distance mode. Second section examines the developments of E-learning and LIS education in India. Third Section spells out the universities are forced to face the following major challenges to adopt e-learning mechanisms, which are to design LIS programmes to fit into the e-learning environment, to provide quality education, the teachers aswellas students are to be trained the information technology advancement, to enhance LIS education e-learning consortium, collaboration, quality assurance with accreditation and cost effective were discussed in details to strengthening the LIS education

    Doctoral Studies in Faculty of Science in Annamalai University

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    This study investigates the rates of successful doctorates awarded in the faculty of science at Annamalai University in the fields of marine biology, physics, chemistry, botany, zoology, biochemistry, maths, statistics and geology. The distribution of Ph.D theses analyzed during the period of 2001-2005. This study led to increase the research activity at various in-depth applied researches in future. An analysis the data revealed that the rates of differences between the subjects as a whole. Pertinent to this study provides statisfical of doctoral research awarded in the faculty of science at Annamalai,University and analyied chronologically, sub-field wise participalion rates by the guides and genderwise

    Use of Internet Resources by Faculty of Annamalai University: A Case Study

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    This study is designed to analyses the patterns of internet resources use by the faculty and impact of internet resources and the problems faced. Internet is not a substitute for the library, to find out the use of internet resources by faculty members for their teaching. For this purpose a well structured questionnaire was distributed among the faculty members working from the five faculties viz: Arts, Science, Education, Engineering, Agriculture and Medicine of Annamalai University. Each faculty 50 potential participants were selected as the sample. The finding of frequency of using library reveals that the professor respondents considerably use the library daily but have average knowledge about internet, the respondents have main problem in lack of time to acquire computer skills to use internet resources. Rating of Internet Resources indicates that an average level of performance

    Case Study of: Internet Access and Usage by Undergraduate Students Vel Tech Technical University, India

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    This study was carried out in order to determine Internet access and usage by the undergraduate students of Vel Tech Technical University, India. Data was obtained from 180 undergraduate students of the institution with the use of a questionnaire. Information collected showed that majority of the cyber cafe around the university environment were privately owned and despite this, students accessed the Internet from their pocket money. It also revealed that majority of the respondents were Internet literate with 33.33% of the respondents browsing the Internet daily; 38.89% weekly, 11.67% fortnightly and 16.11% monthly. It further revealed that the most used Internet facilities are the e-mails, WebPages, search engines and chatting facilities for communication academic activities and for sourcing of information and knowledge

    E-LEARNING: A NEW WAY OF LIBRARY AND INFORMATION SCIENCE EDUCATION THROUGH DISTANCE MODE*

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    Abstract This study explored that the e-learning mechanism is required to provide for quality of Library and Information Science education at university level through the distance learning. This paper is divided into three sections. The first section deals with the LIS education in distance mode. Second section examines the developments of E-learning and LIS education in India. Third Section spells out the universities are forced to face the following major challenges to adopt e-learning mechanisms, which are to design LIS programmes to fit into the e-learning environment, to provide quality education, the teachers aswellas students are to be trained the information technology advancement, to enhance LIS education e-learning consortium, collaboration, quality assurance with accreditation and cost effective were discussed in details to strengthening the LIS education

    Constraining the X-ray - Infrared spectral index of second-timescale flares from SGR1935+2154 with Palomar Gattini-IR

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    The Galactic magnetar SGR1935+2154 has been reported to produce the first known example of a bright millisecond duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs), bolstering the association of FRBs to active magnetars. The detection of a coincident bright X-ray burst has revealed the first observed multi-wavelength counterpart of a FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared wavelengths using the Palomar Gattini-IR observing system in J-band, made possible by a recently implemented detector read-out mode that allowed for short exposure times of 0.84 s with 99.9% observing efficiency. With a total observing time of 12 hours (47728 images) on source, we place median 3σ3\,\sigma limits on the second-timescale emission of <20< 20 mJy (13.1 AB mag). We present non-detection limits from epochs of four simultaneous X-ray bursts detected by the Insight-{\it HXMT} and {\it NuSTAR} telescopes during our observing campaign. The limits translate to an extinction corrected fluence limit of <125< 125 Jy ms for an estimated extinction of AJ=2.0A_J = 2.0 mag. These limits provide the most stringent constraints to date on the fluence of flares at frequencies of 1014\sim 10^{14} Hz, and constrain the ratio of the near-infrared (NIR) fluence to that of coincident X-ray bursts to RNIR<2.5×102R_{\rm NIR} < 2.5 \times 10^{-2}. Our observations were sensitive enough to easily detect a near-infrared counterpart of FRB 200428 if the NIR emission falls on the same power law as that observed across its radio to X-ray spectrum. The non-detection of NIR emission around the coincident X-ray bursts constrains the fluence index of the brightest burst to be steeper than 0.350.35.Comment: 10 pages, 4 figures, submitted to ApJL. Comments welcom

    A Sensitive Search for Supernova Emission Associated with the Extremely Energetic and Nearby GRB 221009A

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    We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 221009A. Due to the extreme rarity of being both nearby (z=0.151z = 0.151) and highly energetic (Eγ,iso1054E_{\gamma,\mathrm{iso}} \geq 10^{54} erg), GRB 221009A offers a unique opportunity to probe the connection between massive star core collapse and relativistic jet formation across a very broad range of γ\gamma-ray properties. Adopting a phenomenological power-law model for the afterglow and host galaxy estimates from high-resolution Hubble Space Telescope imaging, we use Bayesian model comparison techniques to determine the likelihood of an associated SN contributing excess flux to the optical light curve. Though not conclusive, we find moderate evidence (KBayes=101.2K_{\rm{Bayes}}=10^{1.2}) for the presence of an additional component arising from an associated supernova, SN 2022xiw, and find that it must be substantially fainter (<< 67% as bright at the 99% confidence interval) than SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt to constrain the supernova parameters (MNiM_{\mathrm{Ni}}, MejM_{\mathrm{ej}}, and EKEE_{\mathrm{KE}}) under several different assumptions with respect to the host galaxy's extinction. We find properties that are broadly consistent with previous GRB-associated SNe: MNi=0.05M_{\rm{Ni}}=0.05 - 0.25M0.25 \, \rm{M_\odot}, Mej=3.5M_{\rm{ej}}=3.5 - 11.1M11.1 \, \rm{M_\odot}, and EKE=(1.6E_{\rm{KE}} = (1.6 - 5.2)×1052erg5.2) \times 10^{52} \, \rm{erg}. We note that these properties are weakly constrained due to the faintness of the supernova with respect to the afterglow and host emission, but we do find a robust upper limit on the MNiM_{\rm{Ni}} of MNi<0.36MM_{\rm{Ni}}<0.36\, \rm{M_\odot}. Given the tremendous range in isotropic gamma-ray energy release exhibited by GRBs (7 orders of magnitude), the SN emission appears to be decoupled from the central engine in these systems.Comment: 18 pages, accepted to ApJL, 4 tables, 5 figures. Updated abstract in Previe

    A structured jet explains the extreme GRB 221009A

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    Long duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far the brightest burst ever observed. Due to its enormous energy (Eiso ⁣E_\textrm{iso}\!\approx1055^{55} erg) and proximity (z ⁣z\!\approx0.15), GRB 221009A is an exceptionally rare event that pushes the limits of our theories. We present multi-wavelength observations covering the first three months of its afterglow evolution. The X-ray brightness decays as a power-law with slope  ⁣t1.66\approx\!t^{-1.66}, which is not consistent with standard predictions for jetted emission. We attribute this behavior to a shallow energy profile of the relativistic jet. A similar trend is observed in other energetic GRBs, suggesting that the most extreme explosions may be powered by structured jets launched by a common central engine.Comment: Submitted version. 53 pages, 9 figures, 6 table

    Probing pre-supernova mass loss in double-peaked Type Ibc supernovae from the Zwicky Transient Facility

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    Eruptive mass loss of massive stars prior to supernova (SN) explosion is key to understanding their evolution and end fate. An observational signature of pre-SN mass loss is the detection of an early, short-lived peak prior to the radioactive-powered peak in the lightcurve of the SN. This is usually attributed to the SN shock passing through an extended envelope or circumstellar medium (CSM). Such an early peak is common for double-peaked Type IIb SNe with an extended Hydrogen envelope but is uncommon for normal Type Ibc SNe with very compact progenitors. In this paper, we systematically study a sample of 14 double-peaked Type Ibc SNe out of 475 Type Ibc SNe detected by the Zwicky Transient Facility. The rate of these events is ~ 3-9 % of Type Ibc SNe. A strong correlation is seen between the peak brightness of the first and the second peak. We perform a holistic analysis of this sample's photometric and spectroscopic properties. We find that six SNe have ejecta mass less than 1.5 Msun. Based on the nebular spectra and lightcurve properties, we estimate that the progenitor masses for these are less than ~ 12 Msun. The rest have an ejecta mass > 2.4 Msun and a higher progenitor mass. This sample suggests that the SNe with low progenitor masses undergo late-time binary mass transfer. Meanwhile, the SNe with higher progenitor masses are consistent with wave-driven mass loss or pulsation-pair instability-driven mass loss simulations.Comment: Submitted to ApJ. Comments are welcome. arXiv admin note: text overlap with arXiv:2210.0572

    Multi-band analyses of the bright GRB~230812B and the associated SN2023pel

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    GRB~230812B is a bright and relatively nearby (z=0.36z =0.36) long gamma-ray burst that has generated significant interest in the community and therefore has been subsequently observed over the entire electromagnetic spectrum. We report over 80 observations in X-ray, ultraviolet, optical, infrared, and sub-millimeter bands from the GRANDMA (Global Rapid Advanced Network for Multi-messenger Addicts) network of observatories and from observational partners. Adding complementary data from the literature, we then derive essential physical parameters associated with the ejecta and external properties (i.e. the geometry and environment) and compare with other analyses of this event (e.g. Srinivasaragavan et al. 2023). We spectroscopically confirm the presence of an associated supernova, SN2023pel, and we derive a photospheric expansion velocity of v \sim 17×103\times10^3 km s1s^{-1}. We analyze the photometric data first using empirical fits of the flux and then with full Bayesian Inference. We again strongly establish the presence of a supernova in the data, with an absolute peak r-band magnitude Mr=19.41±0.10M_r = - 19.41 \pm 0.10. We find a flux-stretching factor or relative brightness kSN=1.04±0.09k_{\rm SN}=1.04 \pm 0.09 and a time-stretching factor sSN=0.68±0.05s_{\rm SN}=0.68 \pm 0.05, both compared to SN1998bw. Therefore, GRB 230812B appears to have a clear long GRB-supernova association, as expected in the standard collapsar model. However, as sometimes found in the afterglow modelling of such long GRBs, our best fit model favours a very low density environment (log10(nISM/cm3)=2.161.30+1.21\log_{10}({n_{\rm ISM}/{\rm cm}^{-3}}) = -2.16^{+1.21}_{-1.30}). We also find small values for the jet's core angle θcore=1.700.71+1.00 deg\theta_{\rm core}={1.70^{+1.00}_{-0.71}} \ \rm{deg} and viewing angle. GRB 230812B/SN2023pel is one of the best characterized afterglows with a distinctive supernova bump
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