High power universal piezoelectric transformer.

This study describes a multilayer piezoelectric voltage and power transformer that has one direction poling, operates in a wide-frequency range and delivers both step-up and step-down voltages by inverting the electrical connections. In this design, the input and output electrodes are on the same side of the disk and are isolated from each other by a fixed isolation gap. The electrode pattern is a ring/dot structure such that it uses radial mode for both input and output part that are built-in on the same ceramic disk. A prototype transformer was fabricated of size 15 x 2.78 mm2 having mass of 3.8 gm. In the step-down configuration at the constant output power of 6 W, the transformer characteristics across a 100 ohms load were found to be efficiency = 92%, gain = 0.21 input voltage = 110 Vrms, and temperature rise = 20 degrees C from the room temperature. In the step-up configuration at the constant output power of 5 W, the transformer characteristics across a 5 kohms load were found to be efficiency = 97%, gain = 9.5, input voltage = 16 Vrms, and temperature rise = 8 degrees C from the room temperature. A detailed equivalent circuit analysis of the transformer was done, and the results were found to be in excellent agreement with the experimental results.     

Two-Phase Coexistence in Single-Grain BaTiO3–(Mn0.5Zn0.5)Fe2O4 Composites, Via Solid-State Reaction

We have developed a synthesis method of single-grain two-phase BaTiO₃–(Mn_0.5Zn_0.5)Fe₂O₄ nanomaterials via a solid state reaction. The grains of BTO-rich samples were found to have a rod-like morphology with a high aspect ratio and a diameter of 200 nm, whereas the grains of MZF-rich samples had a tetrahedral/octahedral cross-section with a span of 200 nm. Such a synthesis of two-phase perovskite/spinel single-crystal grains with different grain geometries offers the potential to build new types of multiferroic materials.     

Simulation of CI engine flow processes for prediction of performance and emissions with different fuels

Diesel-fuelled direct injection compression ignition engines yield high fuel conversion efficiency due to the use of high compression ratios and thus find their place in varied applications. However, tail pipe emissions of conventional diesel engines are a major source of high levels of oxides of nitrogen (NO_x) and particulate matter. Owing to stringent emission legislation, manufactures and researchers are facing tough competition to make them eco-friendly. The present paper deals with a simulation of extensive numerical experiments carried out on a single-cylinder diesel engine by varying timing of inlet valve closing (25°–55°ABDC) and fuels; rapeseed methyl esters and diesel fuel. For this purpose, a zero-dimensional thermodynamics-based model in C⁺⁺ was developed. The model takes into account the engine speed, fuel injection timing and equivalence ratio, temperature-dependent specific heat ratio and inlet valve close timing. The engine performance is evaluated in terms of thermal efficiency, in-cylinder pressure, heat release rate, and NO and soot emissions. It is observed that a significantly delayed closing of the inlet valve would result in loss of charge, and rapeseed methyl ester could be an attractive and viable alternative to petro-diesel fuel.     

Leveraging AI-enabled 6G-driven IoT for sustainable smart cities

Many scholastic researches have begun around the globe about the competitive technological interventions like 5G communication networks and its challenges. The incipient technology of 6G networks has emerged to facilitate ultrareliable and low-latency applications for sustainable smart cities which are infeasible with the existing 4G/5G standards. Therefore, the advanced technologies like machine learning (ML), block chain, and Internet of Things (IoT) utilizing 6G network are leveraged to develop cost-efficient mechanisms to address the issues of excess communication overhead in the present state of the art. Initially, the authors discussed the key vision of 6G communication technologies, its core technologies (such as visible light communication [VLC] and THz), and the existing issues with the existing network generations (such as 5G and 4G). A detailed analysis of benefits, challenges, and applications of blockchain-enabled IoT devices with application verticals like Smart city, smart factory plus, automation, and XR that form the key highlights for 6G wireless communication network is also presented. In addition, the key applications and latest research of artificial intelligence (AI) in 6G are discussed facilitating the dynamic spectrum allocation mechanism and mobile edge computing. Lastly, an in-depth study of the existing open issues and challenges in green 6G communication network technology, as well as review of solutions and potential research recommendations are also presented.     

Load balancing clustering and routing for IoT-enabled wireless sensor networks

Internet of things (IoT) devices are equipped with a number of interconnected sensor nodes that relies on ubiquitous connectivity between sensor devices to optimize information automation processes. Because of the extensive deployments in adverse areas and unsupervised nature of wireless sensor networks (WSNs), energy efficiency is a significant aim in these networks. Network survival time can be extended by optimizing its energy consumption. It has been a complex struggle for researchers to develop energy-efficient routing protocols in the field of WSNs. Energy consumption, path reliability and Quality of Service (QoS) in WSNs became important factors to be focused on enforcing an efficient routing strategy. A hybrid optimization technique presented in this paper is a combination of fuzzy c-means and Grey Wolf optimization (GWO) techniques for clustering. The proposed scheme was evaluated on different parameters such as total energy consumed, packet delivery ratio, packet drop rate, throughput, delay, remaining energy and total network lifetime. According to the results of the simulation, the proposed scheme improves energy efficiency and throughput by about 30% and packet delivery ratio and latency by about 10%, compared with existing protocols such as Chemical Reaction Approach based Cluster Formation (CHRA), Hybrid Optimal Based Cluster Formation (HOBCF), GWO-based clustering (GWO-C) and Cat Swarm Optimization based Energy-Efficient Reliable sectoring Scheme with prediction algorithms (P_CSO_EERSS). The study concludes that the protocol suitable for creating IoT monitoring system network lifetime is an important criteria.     

Extending Science Gateway Frameworks to Support Big Data Applications in the Cloud

Cloud computing offers massive scalability and elasticity required by many scientific and commercial applications. Combining the computational and data handling capabilities of clouds with parallel processing also has the potential to tackle Big Data problems efficiently. Science gateway frameworks and workflow systems enable application developers to implement complex applications and make these available for end-users via simple graphical user interfaces. The integration of such frameworks with Big Data processing tools on the cloud opens new opportunities for application developers. This paper investigates how workflow systems and science gateways can be extended with Big Data processing capabilities. A generic approach based on infrastructure aware workflows is suggested and a proof of concept is implemented based on the WS-PGRADE/gUSE science gateway framework and its integration with the Hadoop parallel data processing solution based on the MapReduce paradigm in the cloud. The provided analysis demonstrates that the methods described to integrate Big Data processing with workflows and science gateways work well in different cloud infrastructures and application scenarios, and can be used to create massively parallel applications for scientific analysis of Big Data.     

Comparison of in Vitro Release Rates of Nitroglycerin by Diffusion Through a Teflon Membrane to the USP Method

The in vitro release profile of nitroglycerin (GTN) from different transdermal patches through synthetic membranes has been determined and compared to the USP adapted release rate method. Five different nitroglycerin transdermal test formulations were compared to commercially available Nitro-Dur®. All formulations display similar release rate profiles when tested by the USP adapted release rate method. In contrast, significant differences among the tested formulations were observed by using a synthetic Teflon membrane. In these studied an attempt was made to develop a simple, reliable, and reproducible method for testing the release of GTN from different transdermal patches in vitro.     

Biodiesel production from Cedrus deodara oil in different types of ultrasonic reactors and energy analysis

This paper deals with the production of biodiesel using vegetable oil, extracted from Deodar (Cedrus deodara) in various types of ultrasonic reactors. The biodiesel so produced is tested for its property and stability. Biodiesel yield is optimized as a function of reaction time for various ultrasonic reactors. The biodiesel production through the triple-frequency flow cell ultrasonic reactor is found the most energy efficient when compared to other types of ultrasonic reactors. Biodiesel so produced from deodar oil is stable under atmospheric conditions with its various physicochemical properties within the range of acceptable limits of the diesel engine.     

Two-timescale algorithms for simulation optimization of hidden Markov models

We propose two finite difference two-timescale Simultaneous Perturbation Stochastic Approximation (SPSA) algorithms for simulation optimization of hidden Markov models. Stability and convergence of both the algorithms is proved. Numerical experiments on a queueing model with high-dimensional parameter vectors demonstrate orders of magnitude faster convergence using these algorithms over related (N = l)-Simulation finite difference analogues and another Two-Simulation finite difference algorithm that updates in cycles.