6 research outputs found

    Randomness properties of sequence generated using logistic map with novel permutation and substitution techniques

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    In this paper, a design of a chaos-based keystream generator (KSG) using a novel permutation technique with various two-dimensional patterns and a substitution technique with Z4 mapping is proposed. Initially, a chaotic function such as a logistic map is used to generate a pseudo-random number. Then these numbers are converted into binary sequences using binary mapping. In order to achieve statistical properties of the resultant binary sequences, a novel method of KSG is developed by considering parameters such as initial value “x0”, system parameter “r”, novel permutation techniques defined by 2-dimensional patterns, and substitution technique defined over Z4 transformation. The binary sequences so obtained are subjected to randomness tests by applying the National Institute of Standards and Technology (NIST) SP-800-22 (Revision 1a) test suite for investigation of its randomness properties to obtain suitable sequences which can be used as a key for cryptographic applications. From the results obtained, it is found that the binary sequences exhibit better randomness properties as per the cryptographic requirements

    Role of nano-capacitor on dielectric constant enhancement in PEO:NH4SCN:xCeO2 polymer nano-composites: Electrical and electrochemical properties

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    Solution casting technique has been successfully employed to prepare nano-composite films. Various weight ratios of cerium oxide (CeO2) nanoparticle were added to a PEO:NH4SCN:xCeO2 polymer matrix to enhance the ionic conductivity at ambient temperature. The electrical and electrochemical properties of the composite electrolyte systems have been investigated using impedance, dielectric properties (ɛ*, tanδ, and M*), transfer number measurement (TNM), linear sweep voltammetry (LSV), and cyclic voltammetry (CV) techniques. The highest ionic conductivity of ∼8.57 × 10−4 S/cm is obtained for the system incorporated with 3 wt.% of CeO2 filler. This study presented a new approach and the complex permittivity confirmed that the real part value of dielectric constant (ɛ′) for all samples has found to be much higher than the imaginary part (ɛ″) value. The appearance of the peaks at a characteristic frequency in the loss tangent indicates the existence of relaxation. Low dielectric modulus is observed for 3 wt.% of CeO2 incorporated. The TNM measurements confirmed the ionic conductivity of NCSPEs and ion transport tion of films have been found to be 0.84, 0.96 and 0.92 for 1 wt.%, 3 wt.%, and 5 wt.% of CeO2, respectively. The system incorporated with 3 wt.% of CeO2 has discovered to be electrochemically stable up to 1.4 V. From the CV analysis it is noticeable that the energy storage mechanism of the EDLC is a combination of double-layer capacitance and pseudo capacitance. A value of 88.9 F/g is achieved at 20 mV/s

    Structural, Optical and Thermal Characterizations of PVA/MAA:EA Polyblend Films

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    <div><p>Films of polyvinyl alcohol (PVA), Methacrylic Acid - Ethyl Acrylate (MAA:EA) copolymer and their blends PVA:MAA:EA of composition 80:20, 60:40, 50:50, 40:60, 20:80 (wt %) were prepared by using the solution cast technique. The prepared films were investigated by structural, optical and thermal studies. X-ray diffraction (XRD) scans revealed the semicrystalline nature of the blends for lower concentrations of PVA up to 60 wt % and the amorphous nature for higher ones. Fourier transform infra-red spectroscopy (FTIR) of blend samples indicates that there is a compatibility between PVA and MAA:EA copolymers through the formation of hydrogen-bonding between their polar groups.SEM image of polymer blend suggested the presence structural reorganization of polymer chains. UV-Visible spectral analysis revealed that the intensity of the shoulder around 271 nm decreases with increasing MAA:EA content. In DSC analysis, a single glass transition temperature for each blend was observed, which supports the existence of compatibility of such systems. From the observed results, 50:50 (wt %) PVA/MAA:EA is found to be the optimum blending ratio.</p></div

    Immunogenicity and safety of a novel MMR vaccine (live, freeze-dried) containing the Edmonston-Zagreb measles strain, the Hoshino mumps strain, and the RA 27/3 rubella strain: Results of a randomized, comparative, active controlled phase III clinical trial

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    This phase III clinical trial was conducted to evaluate the immunogenicity and safety of the single-dose and multi-dose formulations of a novel MMR vaccine (live, freeze-dried) developed by M/s Cadila Healthcare Limited, India (Cadila MMR vaccine), containing the Hoshino mumps strain, compared to that of an existing MMR vaccine (live, freeze-dried) developed by M/s Serum Institute of India Limited, India (Serum MMR vaccine). These two vaccines have similar measles and rubella strains, but different mumps strains (Hoshino in Cadila MMR vaccine, and L-Zagreb in Serum MMR vaccine). Three hundred and twenty-eight subjects of either sex, aged 15–18 months, were randomized in a 2:1 ratio to receive either the Cadila or Serum MMR vaccine. Immunogenicity assessments (IgG antibodies against measles, mumps, and rubella viruses) were done at baseline and 42 d after vaccination. Solicited (local and systemic) and unsolicited adverse events were recorded for up to 42 d following vaccination. The Cadila MMR vaccine was found to be non-inferior to the Serum MMR vaccine in terms of end-of-study proportion of subjects seropositive for anti-measles antibodies (100.0% in both groups), anti-mumps antibodies (94.5% vs. 94.0%), and anti-rubella antibodies (95.5% vs. 91.0%). Both vaccines were well tolerated by all study participants; the most common adverse event reported in both groups was fever, followed by rash. The results of this phase III clinical trial show that the novel Cadila MMR vaccine is non-inferior to the Serum MMR vaccine

    Enhancement on protonation (H+) with incorporation of flexible ethylene carbonate in CMC–PVA–30 wt % NH4NO3 film

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    In the present work, carboxymethyl cellulose (CMC)–polyvinyl alcohol (PVA)–NH4NO3 with the addition of ethylene carbonate (EC) based polymer blend electrolyte (PBE) was explored. The complexes of PBE with addition of EC revealed that an interaction of the –OH and –COO− of the CMC–PVA blend with the dissociation of H+ from NH4NO3 provides a flexibility pathway for ion hopping. The optimum ionic conductivity at room temperature was found to be 3.92 × 10−3 S/cm for the sample containing 6 wt.% EC with an increment of amorphous phase and thermal stability. Based on the Impedance-Nyquist theoretical approach, it was shown that the ionic conductivity with cation transference number (= 0.48) of the PBE is primarily influenced by the ionic mobility as well as the ions diffusion coefficient. The findings verified that the CMC–PVA–NH4NO3–EC possesses favorable conduction properties upon physical structural modification as a promising polymer electrolyte
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