Springer Science and Business Media LLC

Molybdenum oxide ( $${\text {MoO}}_3$$ ) is a chromogenic and a wide band gap n-type semiconductor. Thickness of thin films is usually observed to have significant influence on various properties of chromogenic materials. $${\text {MoO}}_3$$ thin films of different thicknesses (100 nm, 200 nm and 400 nm) were deposited on glass substrates by thermal evaporation technique. The effect of thickness of deposited thin films on the structural, morphological and optical properties was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM) and UV–visible spectroscopy. XRD analysis revealed the amorphous nature of deposited thin films of different thicknesses. FTIR spectrum showed the characteristic vibrations of intermolecular bonds in molybdenum oxide. The surface morphology of $${\text {MoO}}_3$$ films showed nanoflakes like structures which became densely stacked with increase in film thickness and transformed to large grains with uniform coverage of the substrate surface with randomly oriented morphology. The transmission spectra revealed the slight increase in average transmittance in the visible-NIR region with increase in thickness of thin films. The optical band gap of the deposited thin films of different thicknesses was found to be increasing with increase in thickness of the films which may be attributed to decreased defect centres. The decrease in the values of Urbach energy with increase in thickness may be due to the increased homogeneity and decrease in scattering centres.

In the field of Solar systems, it is necessary for every engineer to start with the solar photovoltaic module (SPVM) design, this paper provides a complete mathematical design specification of the SPVM. The design and development of the SPVM are done to extract its electrical characteristics that are subjective to solar irradiance (G) and temperature (T). This paper model the SPVM with the datasheet of IB Solar-36 series and these modules are connected in parallel to form the Solar Photovoltaic Array (SPVA) is considered for the result verifications. To match the simulation performance of the system accurately with the practical model, this paper uses a novel approach for formulating the equations to find the exact values of shunt resistance (Rsh) and series resistance (Rs) called parasitic effects. The inverse slope method is used to formulate the Parasitic effects from the datasheets, which will extract the exact performance curves of the SPVA. These design principles can be applied to simulate the behavior of any large scale SPVA’s which are present in the system. The simulation and experimental verification using IB Solar-36 polycrystalline modules with varying T and G values for the SPVA are presented.

The wireless communication in the next generation is bound to be driven by massive machine-type communication or in other words Internet-of-things (IoT). In the near future, the need for effective communication and higher data processing rates will require IoT devices to support 5G networks. For 5G IoT applications in the ultra-wideband range (3.1–10.6 GHz), the analog receivers must provide both high-performance and energy efficiency simultaneously. This work addresses the demands of 5G IoT analog receivers by proposing an ultra-low-power low noise amplifier (LNA) employing cross-coupled positive shunt feedback. The proposed LNA is designed in UMC 180 nm deep n-well process, and the post-layout characterization is done using Cadence SpectreRF. The proposed design achieves a peak gain of 9.94 dB and a noise figure of 3.2–1.086 dB along the usable bandwidth of 3.2–9.625 GHz while consuming an ultra-low-power of 493 µW from a 1-V power supply. The maximum input-referred third-order intercept point of 8.81 dBm is attained for an input signal at 2.4 GHz and the interferer as close as 2.425 GHz. The LNA consumes a minimal layout area of only 676.2 µm × 350.7 µm. The proposed LNA has the better figure-of-merit while consuming almost 50% less power than the recently reported sub-mW LNA in literature.

This paper focuses on developing a relationship between the rolling resistance coefficient of an off-road truck tire running over different terrains and at various operating conditions. The various operating conditions include tire speed, vertical load, and inflation pressure. The different terrains include dry and moist sand, flooded surface, snow, dense sand, clayey soil, and sandy loam with moisture. The off-road truck tire size 315/80R22.5 is modeled and validated using the finite element analysis technique, while the terrains are modeled and calibrated using smoothed-particle hydrodynamics technique. Artificial neural network and genetic algorithm (GA) are then used to develop a relationship between the rolling resistance coefficient and the terrains and operating conditions. The results of both algorithms are compared to the simulation results in terms of R-square goodness of fit and the mean squared error. Finally, a numerical equation is presented that determines the rolling resistance coefficient as a function of the terrains parameters and the operating conditions. It was found that both techniques provide a suitable solution, however, the GA provides an explicit equation.

Thermo magnetic response of propagation of waves in rotating graphene tubules is studied with the aid of nonlocal Euler–Bernoulli beam theory within the framework of spectral analysis. The governing dynamic equation of nonlocal rotating graphene tubules under thermo magnetic response is formulated with the help of equation of thermal force, centrifugal force and electromagnetic force. The dispersion equation of nonlocal rotating graphene tubules under thermo magnetic field is derived. The numerical value of non-dimensional wave number is computed and is represented in terms of scattered curves. The scattered curves of graphene tubules at different rotating speed, nonlocal parameter, temperature and magnetic field strength are also drawn. The results give useful information in the study and design of rotary nano-devices such as nano motors, nanoturbines, nano robots etc. The dispersion curves of non-rotating graphene tubules in the absence of thermal and magnetic field are drawn and are compared with the existing literature.

Here a novel polymeric reagent was synthesised by anchoring bromoderivatives of pyrrolidone into the 3D matrix of divinylbenzene cross linked polystyrene and successfully employed for the decarboxylative bromination of trans-cinnamic acid to trans-β-bromostyrene under microwave exposure. 100% conversion and selectivity in a concise period of time under solvent-free condition and simple workup procedure are the foremost attraction of this method. The prepared polymeric reagent exhibited good cyclic stability without any significant reduction in bromine content and satisfactory storage stability under normal laboratory condition.