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In this paper, a slotted circular ultra‐wideband (UWB) microstrip patch antenna is reported. The antenna is designed, simulated, fabricated, and tested experimentally. The antenna operates over a 4.0‐40 GHz (164% fractional bandwidth) range with a return loss of 10 dB and voltage standing wave ratio (VSWR) < 2. The designed monopole antenna is of dimensions 28.1 mm × 17.1 mm with an electrical size of 0.37 λ × 0.23 λ at 4 GHz frequency. The antenna is fabricated on FR‐4 substrate with a dielectric permittivity of 4.4, loss tangent of 0.02, and a thickness of 1.4 mm. The designed antenna exhibits nearly omnidirectional radiation patterns over the entire impedance bandwidth with more than 2.8 dB peak gain for the entire frequency range and 75% of average radiation efficiency. The presented antenna can be used in UWB communications along with C‐band, X‐band, Ku‐band, K‐band, Ka‐band, WLAN, and future wireless applications.

The article aims to optimize the inkjet printing properties to realize highly conductive and mechanically stable printed patterns on the Polyethylene terephthalate (PET) substrate. The key printing parameters such as drop spacing, the number of printed layers, and sintering temperatures were investigated. The test specimens were printed using silver nanoparticle ink and Dimatix 2831 inkjet printer. Then, the printed samples were characterized by electrical conductivity, bending, and adhesion tests. The Analysis of Variance (ANOVA) analysis showed that the number of layers and sintering temperatures were significant factors (p < 0.05) affecting electrical conductivity. The optimum printing parameters for the PET substrate were found to be 20 μm drop spacing, three layers of printing, and 120°C sintering temperature for 30 minutes. The measured optimum resistivity was found to be 5.25 μ -cm. The repetitive bending and adhesion test and ASTM tape test indicated good mechanical stability.

A smart grid will require, to greater or lesser degrees, advanced tools for planning and operation, broadly accepted communications platforms, smart sensors and controls, and real-time pricing. The smart grid has been described as something of an ecosystem with constantly communication, proactive, and virtually self-aware. The use of smart grid has a lot of economical and environmental advantages; however it has a downside of instability and unpredictability introduced by distributed generation (DG) from renewable energy into the public electric systems. Variable energies such as solar and wind power have a lack of stability and to avoid short-term fluctuations in power supplied to the grid, a local storage subsystem could be used to provide higher quality and stability in the fed energy. Energy storage systems (ESSs) would be a facilitator of smart grid deployment and a "small amount" of storage would have a "great impact" on the future power grid. The smart grid, with its various superior communications and control features, would make it possible to integrate the potential application of widely dispersed battery storage systems as well other ESSs. This work deals with a detailed updated review on available ESSs applications in future smart power grids. It also highlights latest projects carried out on different ESSs throughout all around the world.

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An electrochemical sensor for the detection of extremely low concentration of ammonia (1 part per billion, ppb) was fabricated by integrating vanadium monoxide (VOx; x = 0.8–1.2) nanowires on the platinum electrodes. The nanowire-based sensor responds at room temperature non-linearly to a staircase sequence of ammonia from 1 ppb to 100 ppb. The rise and fall time of the nanowire sensor was found to be 10 s and 9 s, respectively. While the immobilization of VO nanowires increased the electrochemical surface area, the defect rich and ionic nature of the VO surface (V2+O2−) facilitated the chemical interaction and adsorption of polar ammonia molecules as evident in the room temperature response of the VO@Pt amperometric electrochemical sensor. The availability of metal centered d-electrons and the semiconductor nature of vanadium monoxide lowered the interfacial resistance of the nanowire-modified sensor enabling the lower detection limit of ammonia. The sensor seems to respond to CH4, H2S and C3H6 as well although the NH3 response is nearly six-fold compared to these common interfering compounds. The results pave the way for a low-cost alternative paper-based sensor to monitor ammonia emissions primarily from confined animal feeding operations (CAFOs).

In this article, the optimum printing parameters were found when using silver nanoparticle ink to print on Kodak 4-Star photo paper substrate. Fujifilm Dimatix 2831 was used as the inkjet printer. The printing parameters of interest included the number of printing layers, the drop spacing, and curing temperature of the ink. Analysis of Variance (ANOVA) analysis of the experimental data reveals sintering temperature to be significant (p < 0.05) to improve the conductivity. Pattern conductivity and surface roughness were used to identify the optimum printing parameters. The optimum printing parameters were found to be 15 μm drop spacing, two printing layer, and a sintering temperature of 90 • C. The best conductivity measured under the above mentioned condition was found to be 5.56 × 10 6 −1 m −1 . Further, the bending test indicated that the printed patterns were unaffected (in terms of conductivity) when flexed around a cylindrical support indicating excellent stability under stress. This study paves the way for developing mechanically robust flexible devices with excellent electrical properties for Internet of Things (IoT) applications.

WiMAX is intended for fourth generation wireless mobile communications where a group of users are provided with a connection and a fixed length queue. In present literature traffic of such network is analyzed based on the generator matrix of the Markov Arrival Process (MAP). In this paper a simple analytical technique of the two dimensional Markov chain is used to obtain the trajectory of the congestion of the network as a function of a traffic parameter. Finally, a two state phase dependent arrival process is considered to evaluate probability states. The entire analysis is kept independent of modulation and coding schemes.