VHE Gamma-ray Afterglow Emission from Nearby GRBs

Gamma-ray Bursts (GRBs) are among the potential extragalactic sources of very-high-energy (VHE) gamma-rays. We discuss the prospects of detecting VHE gamma-rays with current ground-based Cherenkov instruments during the afterglow phase. Using the fireball model, we calculate the synchrotron self-Compton (SSC) emission from forward-shock electrons. The modeled results are compared with the observational afterglow data taken with and/or the sensitivity level of ground-based VHE instruments (e.g. STACEE, H.E.S.S., MAGIC, VERITAS, and Whipple). We find that modeled SSC emission from bright and nearby bursts such as GRB 030329 are detectable by these instruments even with a delayed observation time of ~10 hours.Comment: Proceeding of "Heidelberg International Symposium on High Energy Gamma-Ray Astronomy", held in Heidelberg, 7-11 July 2008, submitted to AIP Conference Proceedings. 4 pages, 3 figures, 1 tabl

Economics and yield performance of some short duration fruit and medicinal crops under agrisilvicultural system in rainfed uplands of Odisha

A field experiment was conducted during 2011-12 in an agrisilvicultural system consisting of two silvicultural species viz. Acacia mangium (mangium) and Gmelina arborea (gamhar) planted in 2000 at a spacing of 8m x 2m and four agricultural crops viz. Ananas comosus (pineapple), Aloe vera (aloevera), Andrographis paniculata(kalmegh) and Curcuma amada (mangoginger) were raised in the 1st week of July, 2011.The maximum volume increment were achieved by mangium with pineapple (16.53 m3/ha). Pineapple also registered the maximum fruit yield of 9981Kgha-1 under mangium and minimum under gamhar (9106 Kgha-1). The fresh leave yield of aloevera (8635Kg ha-1) was maximum under mangium which is statistically at par with gamhar. However, kalmegh recorded maximum dry plant yield of 1239 Kgha-1 under open condition followed by 1072 Kgha-1 under gamhar and 823 Kgha-1 under mangium. Similarly, mangoginger exhibited maximum rhizome yield of 3300 Kgha-1 under open condition followed by 1979 Kgha-1 under gamhar and 1597 Kgha-1 under mangium. The trend of crop yield under both the trees and open condition was: Pineapple >Aloevera>Mangoginger>Kalmegh. A. mangium with pineapple based agrisilvicultural system recorded the highest gross return, net return and BCR as compared to other agrisilvicultural systems and sole crops

On Spatial Consensus Formation: Is the Sznajd Model Different from a Voter Model?

In this paper, we investigate the so-called ``Sznajd Model'' (SM) in one dimension, which is a simple cellular automata approach to consensus formation among two opposite opinions (described by spin up or down). To elucidate the SM dynamics, we first provide results of computer simulations for the spatio-temporal evolution of the opinion distribution $L(t)$, the evolution of magnetization $m(t)$, the distribution of decision times $P(\tau)$ and relaxation times $P(\mu)$. In the main part of the paper, it is shown that the SM can be completely reformulated in terms of a linear VM, where the transition rates towards a given opinion are directly proportional to frequency of the respective opinion of the second-nearest neighbors (no matter what the nearest neighbors are). So, the SM dynamics can be reduced to one rule, ``Just follow your second-nearest neighbor''. The equivalence is demonstrated by extensive computer simulations that show the same behavior between SM and VM in terms of $L(t)$, $m(t)$, $P(\tau)$, $P(\mu)$, and the final attractor statistics. The reformulation of the SM in terms of a VM involves a new parameter $\sigma$, to bias between anti- and ferromagnetic decisions in the case of frustration. We show that $\sigma$ plays a crucial role in explaining the phase transition observed in SM. We further explore the role of synchronous versus asynchronous update rules on the intermediate dynamics and the final attractors. Compared to the original SM, we find three additional attractors, two of them related to an asymmetric coexistence between the opposite opinions.Comment: 22 pages, 20 figures. For related publications see http://www.ais.fraunhofer.de/~fran

Clonal evaluation for early growth performance of Eucalyptus in South Gujarat, India

This study was carried out in College of Forestry, Navsari Agricultural University, Navsari, Gujarat. Total 20 clones having age of 5 ½ years were selected for early growth evaluation at field condition. There was a significant variation (P < 0.05) among 20 clones of Eucalyptus for growth parameters viz., tree height, DBH, mid-diameter, form quotient and volume of standing tree. Tree height varied from 18.5 to 23.6 m with DBH range of 11.47 to 16.07 cm. Mid-diameter indirectly helps to assess the tapering of tree and it ranged from 6.99 to 10.57 cm among 20 clones. The form quotient was used while calculation of volume of Eucalyptus clones. The form quotient varied between 0.58 and 0.71 with overall mean of 0.63 at studied site. Volume of standing tree ranged from 0.12 to 0.28 m3. The overall results showed that clones such as C12 (P2045), C17 (B2253), C4 (P413), C8 (P526), C7 (P498), C16 (SRO16) and C11 (P3020) performed superior for early growth attribute and stem form and these clones suggested for large scale plantation in South Gujarat region

Electromagnetic transition from the 4+^+ to 2+^+ resonance in 8^8Be measured via the radiative capture in 4^4He+4^4He

An earlier measurement on the 4$^+$ to 2$^+$ radiative transition in $^8$Be provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. The present paper reports a more elaborate and precise measurement for this transition, via the radiative capture in the $^4$He+$^4$He reaction, improving the accuracy by about a factor of three. The {\it ab initio} calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and {\it ab initio} calculations.Comment: 5 pages and 7 figures, Submitted to Physical Review Letter

Characterization of shape and dimensional accuracy of incrementally formed titanium sheet parts with intermediate curvatures between two feature types

Single point incremental forming (SPIF) is a relatively new manufacturing process that has been recently used to form medical grade titanium sheets for implant devices. However, one limitation of the SPIF process may be characterized by dimensional inaccuracies of the final part as compared with the original designed part model. Elimination of these inaccuracies is critical to forming medical implants to meet required tolerances. Prior work on accuracy characterization has shown that feature behavior is important in predicting accuracy. In this study, a set of basic geometric shapes consisting of ruled and freeform features were formed using SPIF to characterize the dimensional inaccuracies of grade 1 titanium sheet parts. Response surface functions using multivariate adaptive regression splines (MARS) are then generated to model the deviations at individual vertices of the STL model of the part as a function of geometric shape parameters such as curvature, depth, distance to feature borders, wall angle, etc. The generated response functions are further used to predict dimensional deviations in a specific clinical implant case where the curvatures in the part lie between that of ruled features and freeform features. It is shown that a mixed-MARS response surface model using a weighted average of the ruled and freeform surface models can be used for such a case to improve the mean prediction accuracy within ±0.5 mm. The predicted deviations show a reasonable match with the actual formed shape for the implant case and are used to generate optimized tool paths for minimized shape and dimensional inaccuracy. Further, an implant part is then made using the accuracy characterization functions for improved accuracy. The results show an improvement in shape and dimensional accuracy of incrementally formed titanium medical implants

Background measurements and detector response studies for ISMRAN experiment

We report the measurement of the non-reactor environmental backgrounds and the detector response with the Indian Scintillator Matrix for Reactor Anti-Neutrinos (ISMRAN), which is $\sim$1 ton detector setup by volume, consisting of 10$\times$9 (10 rows and 9 columns) Plastic Scintillator Bars (PSBs) array at BARC, Mumbai, India. ISMRAN is an above-ground anti-neutrino ($\mathrm{\overline\nu_{e}}$) experiment at very short baseline located at Dhruva research reactor facility. It is enclosed by a shielding made of 10 cm thick lead and 10 cm thick borated polyethylene to minimize the backgrounds and is mounted on a movable base structure, situated at $\sim$ 13 m away from the reactor core. These measurements are useful in the context of the ISMRAN detector setup that will be used to detect the reactor $\mathrm{\overline\nu_{e}}$ and measure its energy spectrum through the inverse beta decay (IBD) process. In this paper, we present the energy resolution model and energy non-linearity model of PSB and the cosmogenic muon-induced background, based on the sum of their energy depositions and number of hit bars. Reconstructed sum energy spectrum and number of hit bars distribution for $\mathrm{{}^{22}Na}$ radioactive source has been compared with Geant4 based Monte Carlo simulations. These experimentally measured results will be useful for discriminating the correlated and uncorrelated background events from the true IBD events in reactor ON and OFF conditions inside the reactor hall.Comment: 4 pages, 4 figures. arXiv admin note: text overlap with arXiv:2208.0349