An enhanced flower pollination algorithm‐based chaff point generation method with hardware implementation in WBAN

In wireless body area networks (WBAN), device authentication and key agreement are the critical issues. In any real‐world cryptographic system, issues like these can be handled by one of the most practical bio‐cryptosystem schemes popularly known as fuzzy vault (FV). The secret key is encoded in a polynomial equation merged with physiological value and then combined with chaff (noise) points forming the FV. The most critical and computational intensive task in the FV is the chaff point generation, that is used to hide the valid point inside the vault pattern. In this paper, we propose an Enhanced Flower Pollination Algorithm based Chaff Point generation method with Hardware (EFPCH) implementation and have been proved to be a computationally fast and feasible algorithm for hardware implementation. The security of the FV depends on the infeasibility of the polynomial reconstruction and also in large number of chaff point. The existing methods for chaff point generation had taken less number of valid points and generate a maximum of 200 chaff points. But in our experimental result, we generated large number of chaff point (1:12) with a considerable amount of valid points over the existing algorithm. This work describes the key agreement model and implementation step required for identifying External programmer attached to the patient pacemaker. However, existing key agreement schemes have too many computational intensive tasks, making it unsuitable for system‐on‐chip (SoC) implementation. In the result of the described work, a practical SoC implementation of the wireless environment in WBAN is experimented. The results show that our proposed model has a more efficient implementation in generating larger chaff points and performs better than other current methods.     

Flash pyrolysis of palmyra palm (Borassus flabellifer) using an electrically heated fluidized bed reactor

Agriculture residues such as palmyra fruit bunch are one of the biomass categories that can be utilized for conversion to bio-oil by using pyrolysis process. Flash pyrolysis experiments have been conducted in the electrically heated fluidized bed reactor to determine the effect of pyrolysis temperature, particle size, and sweep gas flow rate on the pyrolysis product yield. In this study the maximum oil yield of 48.2% was achieved at a temperature of 500°C, particle size of 1 mm, and at a sweep gas flow rate of 2 m³/h. The results show that the effects of pyrolysis temperature and particle size on pyrolysis yields are more significant than that of sweep gas flow rate. Bio-oil was identified as a biofuel candidate and it was further upgraded for better-quality biofuel. Various physical and elemental analyses were performed for bio-oil and the same characteristics study was also carried out for biofuel.     

RNS-to-Binary Converters for Two Four-Moduli Sets {2n−1,2n,2n+1,2n+1−1} and {2n−1,2n,2n+1,2n+1+1}

In this paper, reverse converters for two recently proposed four-moduli sets {2ⁿ - 1,2ⁿ,2ⁿ + 1,2ⁿ+1 - 1} and {2ⁿ - 1, 2ⁿ, 2ⁿ + 1, 2ⁿ+1 + 1} are described. The reverse conversion in the three-moduli set {2ⁿ - 1,2ⁿ,2ⁿ + 1} has been optimized in literature. Hence, the proposed converters are based on two new moduli sets {(2ⁿ(2²ⁿ-1)),2ⁿ⁺¹-1} and {(2ⁿ(2²ⁿ-1)), 2ⁿ⁺¹+1} and use mixed radix conversion. The resulting designs do not require any ROM. Both are similar in their architecture except that the converter for the moduli set {2ⁿ - 1, 2ⁿ, 2ⁿ + 1, 2ⁿ+1 + 1} is slightly complicated due to the difficulty in performing reduction modulo (2ⁿ⁺¹+1) as compared with modulo (2ⁿ⁺¹-1). The proposed conversion techniques are compared with earlier realizations described in literature with regard to conversion time as well as area requirements.     

Mediated electrochemical oxidation of phenol in continuous feeding mode using Ag (II) and Ce (IV) mediator ions in nitric acid: A comparative study

Mediated electrochemical oxidation (MEO) process is one among the latest treatment technologies for the destruction of toxic organic pollutants under ambient temperatures and at atmospheric pressure. The process is a further extension of the conventional electrochemical treatment for the removal of toxic organics with powerful mediator oxidants in acidic medium. In this report the experimental results of using silver and cerium as mediator ions were compared with respect to their electro-oxidation behavior within the limitations of each mediator metal ion and their destruction efficiencies were compared for destructing phenol in continuous feeding mode. The following conclusions were drawn: (i) the optimum nitric acid concentration was found to be 8 and 3 M and the optimum temperature was found to be 60 and 80 °C for silver and cerium electro-oxidations, respectively; (ii) in the case of Ag (II)-MEO of phenol the maximum destruction efficiency achieved was 98% at 70 °C based on CO₂ evolved; (iii) for Ce (IV)-MEO of phenol the maximum destruction efficiency achieved was 93% at 90 °C based on CO₂. The results may provide baseline information on the use of suitable mediator metal ion in treating the target organic wastes by MEO process.     

Inhibition of Plasmodium falciparum Lysyl-tRNA Synthetase via a Piperidine-Ring Scaffold Inspired Cladosporin Analogues

Plasmodium falciparum lysyl-tRNA synthetase (PfKRS) represents a promising therapeutic anti-malarial target. Cladosporin was identified as a selective and potent PfKRS inhibitor but lacks metabolic stability. Here, we report chemical synthesis, biological evaluation and structural characterization of analogues where the tetrahydropyran (THP) frame of cladosporin is replaced with the piperidine ring bearing functional group variations. Thermal binding, enzymatic, kinetic and parasitic assays complemented with X-ray crystallography reveal compounds that are moderate in potency. Co-crystals of Cla−B and Cla−C with PfKRS reveal key atomic configurations that allow drug binding to and inhibition of the enzyme. Collectively these piperidine ring scaffold inhibitors lay a framework for further structural editing and functional modifications of the cladosporin scaffold to obtain a potent lead.     

Structural,morphological, optical and gas sensing properties of pure and Ce doped SnO<Subscript>2</Subscript> thin films prepared by jet nebulizer spray pyrolysis (JNSP) technique

Pure and cerium (Ce) doped tin oxide (SnO₂) thin films are prepared on glass substrates by jet nebulizer spray pyrolysis technique at 450 °C. The synthesized films are characterized by X-ray diffraction (XRD), scanning electron microscopy, energy dispersive analysis X-ray, ultra violet visible spectrometer (UV–Vis) and stylus profilometer. Crystalline structure, crystallite size, lattice parameters, texture coefficient and stacking fault of the SnO₂ thin films have been determined using X-ray diffractometer. The XRD results indicate that the films are grown with (110) plane preferred orientation. The surface morphology, elemental analysis and film thickness of the SnO₂ films are analyzed and discussed. Optical band gap energy are calculated with transmittance data obtained from UV–Visible spectra. Optical characterization reveals that the band gap energy is found decreased from 3.49 to 2.68 eV. Pure and Ce doped SnO₂ thin film gas sensors are fabricated and their gas sensing properties are tested for various gases maintained at different temperature between 150 and 250 °C. The 10 wt% Ce doped SnO₂ sensor shows good selectivity towards ethanol (at operating temperature 250 °C). The influence of Ce concentration and operating temperature on the sensor performance is discussed. The better sensing ability for ethanol is observed compared with methanol, acetone, ammonia, and 2-methoxy ethanol gases.     

Doping effect of urea on growth,spectral, thermal,mechanical, electrical,nonlinear and optical studies of Sr(HCOO)<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O crystal: enhanced third-order NLO properties with a high laser-induced damage threshold

Pure and urea doped (with 3 different concentrations, viz. 0.005, 0.05, and 0.1 M) strontium formate dihydrate (SFD, Sr(HCOO)₂·2H₂O) single crystals were grown from aqueous solutions by using slow solvent evaporation technique. In order to understand the effect of urea doping on the structural, chemical, thermal, morphological, optical properties of SFD crystals, the grown crystals were characterized by carrying out CHN analysis, powder X-ray diffraction, high resolution X-ray diffraction, Fourier transform infrared spectral, thermogravimetric, UV–Vis–NIR spectral, photoluminescence spectral, second harmonic generation efficiency, and Z-scan measurements. The results obtained indicate that the urea molecule have entered into the SFD crystal matrix and has improved the crystallinity. Also, the results indicate that urea doping significantly tunes the optical and thermal properties without significantly distorting the crystal structure of SFD crystal. The laser damage threshold (LDT) energy for the grown crystal has been measured by using a Q-switched Nd:YAG laser as a source in single-shot mode (1064 nm, 10 Hz, 420 mJ). The result of laser damage threshold (LDT) energy indicates that grown title crystal has excellent resistance to laser radiation than those of some known inorganic NLO materials. Its third-order nonlinear optical properties were investigated by Z-scan technique and proved that the grown crystal possesses two-photon absorptions (TPA) and the self-defocusing effect.