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Background: The Yagi-Uda antenna is a highly directive antenna used widely in many applications including pulsed Doppler radars to study the dynamics of the atmosphere. Yagi antennas configured in planar array configurations in phased array radars to achieve high peak powers to probe the atmosphere from troposphere. In this paper, a two-element Yagi-Uda antenna design is presented to investigate the ionospheric irregularities from the Gadanki Ionospheric Radar Interferometer. A new approach devised for the first time to design the two element, wide beam width tilted Yagi antenna, where folded dipole acts as active driver element and reflector as parasitic element. Methods: Several design techniques have been studied and new approach has been employed in designing the antenna and simulations have been carriedout and optimized the performance at 30 MHz with 14o tilt towards geometric north from vertical (zenith) direction for the maximum back scattered echo gain. Based on the design antenna has been fabricated and the system performance has been evaluated. Detailed validation methods have been listed to validate the parameters like reflection coefficient, gain, bandwidth and front-to-back ratio. Results: The antenna is designed and simulated results with 4NEC2 provided the optimized parameters before fabrication. The measured results indicate that the antenna has a gain of 5.65dBi and a reflection coefficient of -30 dB and these results are in close agreement with the simulation results. The band width obtained is about 2MHz is very good for the ionospheric remote sensing applications. The peak power handling capability upto 1kW shows the reliable system design for continuous and long term use of the system. Conclusion: Two element wide beam width 14o tilted Yagi-Uda antenna at 30MHz has been designed, simulated and optimized. Realized system performance validated to use for ionospheric radar remote sensing application. Details of the test methodologies are explained and the same have been executed to characterize the performance of the fabricated antenna with simulation results by measuring reflection coefficient, gain, radiation pattern. All the measured results have very close agreement with the simulation results and satisfy the design requirements to fit into 30 MHz radar antenna array for dedicated ionospheric probing. In future, we intended to carry out the radiation pattern simulation of the 20x8 phased array antennas to describe the overall radiation pattern.

Background: Solid polymer electrolyte (SPEs) films based on poly (vinylidene fluoride-co-hexafluoropropylene) P(VDF–HFP) and sodium thiocyanate (NaSCN) are prepared using the solution casting technique. Methods: Ionic liquid (IL; 1-ethyl-3-methyl-imidazolium tricyanomethanide ([EMIM] [TCM]) is incorporated into the prepared polymer-salt complex matrix to enhance its ionic conductivity further. Polarized optical microscopy (POM) shows a change in the surface morphology of IL doped polymer electrolyte films. The composite nature of polymer electrolyte films is confirmed using Fourier transform infrared (FT-IR) spectroscopy via studying ion-ion and ion-polymer interactions. The structural morphology of ionic liquid doped polymer electrolyte films (ILDPE) confirms the complexation between the ionic liquid ([EMIM][TCM]), salt (NaSCN) and polymer P(VDF-HFP). This is further confirmed using DSC and XRD measurements. The XRD structural analysis confirms that the intensity of crystalline peaks present in IL doped solid polymer electrolyte films decreases as compared to that of the pure polymer as well as polymer salt complex system. XRD clearly indicates the enhancement in its amorphous nature, which is necessary to increase the conductivity. Results: The incorporation of IL into polymer salt-complex matrix leads to changes in the melting of polymer electrolytes, confirmed by DSC thermograms. Polymer electrolyte films are also characterized using impedance spectroscopy (IS) to check their electrical properties. The highest ionic conductivity is found to be 7.80×10-4 S cm-1 for 6 wt% IL doped polymer electrolyte film. Conclusion: The Linear sweep voltammetry (LSV) analysis shows that the optimized polymer gel electrolyte is electrochemically stable up to 1.5 V. The calculated value of ionic transference number (tion) is found to be 0.985. A laboratory scale electrical double layer capacitor (EDLC) has been fabricated using this highly conducting polymer electrolyte film. The specific capacitance value is found to be 1.31 F g-1.

Each human genome includes de novo mutations that arose during gametogenesis. While these germline mutations represent a fundamental source of new genetic diversity, they can also create deleterious alleles that impact fitness. Whereas the rate and patterns of point mutations in the human germline are now well understood, far less is known about the frequency and features that impact de novo structural variants (dnSVs). We report a family-based study of germline mutations among 9,599 human genomes from 33 multigenerational CEPH-Utah families and 2,384 families from the Simons Foundation Autism Research Initiative. We find that de novo structural mutations detected by alignment-based, short-read WGS occur at an overall rate of at least 0.160 events per genome in unaffected individuals, and we observe a significantly higher rate (0.206 per genome) in ASD-affected individuals. In both probands and unaffected samples, nearly 73% of de novo structural mutations arose in paternal gametes, and we predict most de novo structural mutations to be caused by mutational mechanisms that do not require sequence homology. After multiple testing correction, we did not observe a statistically significant correlation between parental age and the rate of de novo structural variation in offspring. These results highlight that a spectrum of mutational mechanisms contribute to germline structural mutations and that these mechanisms most likely have markedly different rates and selective pressures than those leading to point mutations.

In this study we are presenting the synthesis of MnO2 nanorods using hydrothermal method assisted by facile tri-ethanolamine-ethoxylate. Structural (x-ray diffraction, Rietveld refinement), functional (Fourier Transform Infrared spectroscopy and x-ray Photoelectron Spectroscopy) and morphological (Field emission scanning electron microscope, Transmission electron microscopy) characterization conform the β-MnO2 nanostructure with a rod-like morphology and uniform thickness. The morphological variations of the nanorod thickness can be easily controlled by simply monitoring the reaction temperature. Comparative investigations of β-MnO2 samples synthesized at two different reaction temperatures (viz. 100 °C and 120 °C) used as a supercapacitive electrode material have been performed with the aid of different electrochemical techniques. With different electrolytes (Li2SO4 and Na2SO4), supercapacitor device is tested using Cyclic voltammetry, impedance spectroscopy and galvanostatic charge discharge. Interestingly, the low temperature synthesized β-MnO2 nanorods sample exhibit superior electrochemical performance in 1 mol l−1 Li2SO4 electrolyte in terms of high specific capacitance (462 Fg−1 at10 mVs−1), energy density (9.72 WhKg−1), and outstanding cyclic stability (90.26% over 2000 cycles).

In this review, the efforts done by different research groups to enhance the performance of the electric double-layer capacitors (EDLCs), regarding the effect of the modification of activated carbon structures on the electrochemical properties, are summarized. Activated carbon materials with various porous textures, surface chemistry, and microstructure have been synthesized using several different techniques by different researchers. Micro-, meso-, and macroporous textures can be obtained through the activation/carbonization process using various activating agents. The surface chemistry of activated carbon materials can be modified via: (i) the carbonization of heteroatom-enriched compounds, (ii) post-treatment of carbon materials with reactive heteroatom sources, and (iii) activated carbon combined both with metal oxide materials dan conducting polymers to obtain composites. Intending to improve the EDLCs performance, the introduction of heteroatoms into an activated carbon matrix and composited activated carbon with either metal oxide materials or conducting polymers introduced a pseudo-capacitance effect, which is an additional contribution to the dominant double-layer capacitance. Such tricks offer high capacitance due to the presence of both electrical double layer charge storage mechanism and faradic charge transfer. The surface modification by attaching suitable heteroatoms such as phosphorus species increases the cell operating voltage, thereby improving the cell performance. To establish a detailed understanding of how one can modify the activated carbon structure regarding its porous textures, the surface chemistry, the wettability, and microstructure enable to enhance the performance of the EDLCs is discussed here in detail. This review discusses the basic key parameters which are considered to evaluate the performance of EDLCs such as cell capacitance, operating voltage, equivalent series resistance, power density, and energy density, and how these are affected by the modification of the activated carbon framework.