639 research outputs found

    Implementation of Physical Layer Key Distribution using Software Defined Radios

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    It was well known from Shannon’s days that characteristics of the physical channel like attenuation, fadingand noise can impair reliable communication. But it was more recently that the beneficial side effects of channelcharacteristics in ensuring secret communication started getting attention. Studies have been made to quantify theamount of secrecy that can be reaped by combining channel coding with security protocols. The Wiretap channelproposed by Wyner is arguably one of the oldest models of physical layer security protocols. In this paper, wepresent a brief tutorial introduction to the Wiretap channel, followed by an application of the physical layer modelto a class of Key Distribution protocols. We present results from an implementation of key distribution protocolsusing Software Defined Radio tools along with physical RF hardware peripherals. We believe this approach is muchmore tangible and informative than computer based simulation studies.Defence Science Journal, 2013, 63(1), pp.6-14, DOI:http://dx.doi.org/10.14429/dsj.63.375

    Design of a high-power compact SRF linac for industrial applications of e-beam irradiation

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    Fermilab has developed a novel concept for an industrial electron linac using Nb3Sn coating technology and conduction cooling. These conduction-cooled linacs can generate electron beam energies up to 10 MeV in continuous-wave operation and reach higher power (>=1 MW) by combing several modules. Compact and light enough to mount on mobile platforms, our machine is anticipated to enable new in-situ environmental remediation applications such as waste-water treatment for urban areas, X-ray medical device sterilization, and innovative pavement applications. We highlight a few aspects of a 1 MW design of such a machine in this paper. A detailed plan is in Dhuley et al. (2022) Phys. Rev. Accel. Beams 25, 041601.Comment: arXiv admin note: substantial text overlap with arXiv:2112.0923

    Captive Breeding and Nursery Rearing of the Indian Seahorse, Hippocampus kuda (Teleostei: Syngnathidae)

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    Breeding of laboratory-reared 21 pairs of broodstock Hippocampus kuda (Bleeker 1852) and rearing of their young ones indicated that 262.00 ± 59.00 offsprings were released during each spawning. A newly born seahorse was (mean ± SE) 7.83 ± 0.11 mm in length with a weight of 1.17 ± 0.009 mg. It could attain a mean length of 31.14 ± 0.66 mm with a mean weight of 16.13 ± 0.60 mg in 30 days when fed ad libitum with Artemia nauplii. The mean survival per brood cycle was enhanced to 65.22 ± 1.87% from almost less than 1.0% by improving the rearing conditions

    Analysis of harmonics using wavelet technique

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    This paper develops an approach based on wavelet technique for the estimation of harmonic presents in power system signals. The proposed technique divides the power system signals into different frequency sub-bands corresponding to the odd harmonic components of the signal. The algorithm helps to determine both the time and frequency information from the harmonic frequency bands. The comparative study will be done with the input and the results attained from the wavelet transform (WT) for different conditions and Simulation results are given

    Phytochemical constituent and antioxidant activity of extract from the leaves of Ocimum basilicum

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    Ocimum basilicum leaf extracts of were investigated for phytochemical constituent and antioxidant activity. Tests for tannins, steroids, terpenoids, flavonoids and cardiac glycosides were positive in both ethanolic and aqueous extracts. The ethanolic extract of O. basilicum had a DPPH scavenging activity of 85.2% at 250μg/ml and a reductive potential of 0.79 at 100 μg/ml. These values were comparable with those of gallic acid, 91.1% at 250 μg/ml and ascorbic acid, 0.76 at 60 μg/ml as standards for DPPH scavenging activity and reductive potential, respectively. These findings suggest that the rich phytochemical content of O. basilicum and its good antioxidant activity may be responsible for its popular and wide traditional use
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