Search results

End-to-end latency in network affects the overall performance in number of ways. It is one of the major tasks to minimize the end-to-end latency in cognitive radio ad hoc networks (CRAHN), as the transmission of packets passes through every hop of the routing path. This paper aims to propose a new reactive multicast routing protocol, namely, improved frog leap inspired protocol (IFLIP) to reduce the overall end-to-end latency in CRAHN.

It is difficult to solve the problems that emerge in optimization. Routing is the procedure for choosing the best network path. This paper proposes a novel algorithm by improving the FLIP to use an ideal route, which progressively reduces the congestion level on various routing path by considering the spectrum accessibility and the service rate of each hop in CRAHN.

Result of this research work concludes that IFLIP significantly outperforms other baseline schemes (namely, TIGHT and Greedy TIGHT) in minimizing the end-to-end latency in CRAHN.

It is proved that IFLIP gives a better ratio of packet delivery under varying primary users and secondary users. IFLIP results in increased packet deliver ratio, reduced end-to-end latency and better throughput.

This article critically examines the recent opposition to environmental, social, and governance (ESG) initiatives, which have been increasingly scrutinized and politicized, particularly in the US. The article deals with the inherent political and economic tensions that challenge the adoption and effectiveness of ESG initiatives, highlighting the debate over shareholder versus stakeholder priorities and the broader implications for corporate social responsibility. The criticism of ESG is deeply rooted in the concerns over its impact on financial performance and perceived regulatory overreach, leading to a preference for maximizing shareholder value at the expense of broader societal goals. This chapter explores the potential future scenarios for ESG, considering the shifting landscape of sustainability in business practices amidst growing conservative resistance. This analysis is crucial for understanding the trajectory of sustainable finance and corporate contributions to environmental and social objectives in a polarized socio-political context.

This information will be useful in the selection of materials and technology for the detection and removal of mercury ions at a low cost and with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity.

Different nano- and bio-materials allowed for the development of a variety of biosensors – colorimetric, chemiluminescent, electrochemical, whole-cell and aptasensors – are described. The materials used for their development also make it possible to use them in removing heavy metals, which are toxic contaminants, from environmental water samples.

This review focuses on different technologies, tools and materials for mercury (heavy metals) detection and remediation to environmental samples.

This review gives up-to-date and systemic information on modern nanotechnology methods for heavy metal detection. Different recognition molecules and nanomaterials have been discussed for remediation to water samples. The present review may provide valuable information to researchers regarding novel mercury ions detection sensors and encourage them for further research/development.

This paper aims to propose a new MLI topology with reduced number of switches for photovoltaic applications. Multilevel inverters (MLIs) have been found to be prospective for renewable energy applications like photovoltaic cell, as they produce output voltage from numerous separate DC sources or capacitor banks with reduced total harmonic distortion (THD) because of a staircase like waveform. However, they endure from serious setbacks including larger number of capacitors, isolated DC sources, associated gate drivers and increased control difficulty for higher number of voltage levels.

This paper proposes a new three-phase multilevel DC-link inverter topology overpowering the previously mentioned problems. The proposed topology is designed for five and seven levels in Matlab/Simulink with gating pulse using multicarrier pulse width modulation. The hardware results are shown for a five-level MLI to witness the viability of the proposed MLI for medium voltage applications.

The comparison of the proposed topology with other conventional and other topologies in terms of switch count, DC sources and power loss has been made in this paper. The reduction of switches in proposed topology results in reduced power loss. The simulation and hardware show that the output voltage yields a very close sinusoidal voltage and lesser THD.

The proposed topology can be extended for any level of output voltage which is helpful for sustainable source application.

Multilevel inverter (MLI) is a prevailing sensible alternative to two-level inverters that offer a high-quality output voltage waveform, wherein the multiple input direct current (DC) levels are established by using isolated DC sources, batteries and renewable energy sources. The purpose of this paper is to develop MLI to offer lower total harmonic distortion (THD), higher output voltage levels and reduced switching components for high power applications.

In this paper, a new tapped sources stack succored modified HX bridge MLI (TSSSMHXBMLI) topology is proposed which includes two modules, such as tapped sources stack (TSS) and modified HX bridge inverter, which perform their function in a single stage. Also, this paper outlines the formulaic implementation of the multicarrier/sub-harmonic pulse width modulation (MCPWM/SHPWM) in a Xilinx Spartan3E-500 field programmable gate array (FPGA) is suitable for the developed MLI.

The feasibility of the suggested topology is well proved by both simulation and experiment results.

This paper examines a new topology of TSSSMHXBMLI with a view to minimize total count of switching components against basic MLI topologies. The operating sequence of the suggested TSSSMHXBMLI topology is verified with the simulation study followed by an experimental investigation.

The simulation and experimental results of suggested MLI topology reveals to obtain lower THD, higher output voltage levels and reduced switching components for high power applications.

Multilevel inverters become very popular in medium voltage applications owing to their inherent capability of reconciling stepped voltage waveform with reduced harmonic distortion and electromagnetic interference. They have several disadvantages like more number of switching devices required and devices with high voltage blocking and need additional dc sources count to engender particular voltage. So this paper aims to propose a novel tri-source symmetric cascaded multilevel inverter topology with reduced number of switching components and dc sources.

A novel multilevel inverter has been suggested in this study, offering minimal switch count in the conduction channel for the desired voltage level under symmetric and asymmetric configurations. This novel topology is optimized to prompt enormous output voltage levels by employing constant power switches count and/or dc sources of voltage. The topology claims its advantages in generating higher voltage levels with lesser number of voltage sources, gate drivers and dc voltage sources.

The consummation of the proposed arrangement is verified in Matlab/Simulink R2015b, and an experimental prototype for 7-level, 13-level, 21-level, 29-level, 25-level and 49-level operation modes is constructed to validate the simulation results.

The proposed topology operated with six new algorithms for asymmetrical configuration to propel increased number of voltage levels with reduced power components.

This study aims to review the recent advancements in high entropy alloys (HEAs) called high entropy materials, including high entropy superalloys which are current potential alternatives to nickel superalloys for gas turbine applications. Understandings of the laser surface modification techniques of the HEA are discussed whilst future recommendations and remedies to manufacturing challenges via laser are outlined.

Materials used for high-pressure gas turbine engine applications must be able to withstand severe environmentally induced degradation, mechanical, thermal loads and general extreme conditions caused by hot corrosive gases, high-temperature oxidation and stress. Over the years, Nickel-based superalloys with elevated temperature rupture and creep resistance, excellent lifetime expectancy and solution strengthening L12 and γ´ precipitate used for turbine engine applications. However, the superalloy’s density, low creep strength, poor thermal conductivity, difficulty in machining and low fatigue resistance demands the innovation of new advanced materials.

HEAs is one of the most frequently investigated advanced materials, attributed to their configurational complexity and properties reported to exceed conventional materials. Thus, owing to their characteristic feature of the high entropy effect, several other materials have emerged to become potential solutions for several functional and structural applications in the aerospace industry. In a previous study, research contributions show that defects are associated with conventional manufacturing processes of HEAs; therefore, this study investigates new advances in the laser-based manufacturing and surface modification techniques of HEA.

The AlxCoCrCuFeNi HEA system, particularly the Al0.5CoCrCuFeNi HEA has been extensively studied, attributed to its mechanical and physical properties exceeding that of pure metals for aerospace turbine engine applications and the advances in the fabrication and surface modification processes of the alloy was outlined to show the latest developments focusing only on laser-based manufacturing processing due to its many advantages.

It is evident that high entropy materials are a potential innovative alternative to conventional superalloys for turbine engine applications via laser additive manufacturing.

This paper aims to investigate the effect and parametric optimization of process parameters during milling of glass fibre-reinforced plastics (GFRP) composites using grey relational analysis (GRA).

Experiments are conducted using helix angle, spindle speed, feed rate, depth of cut and fibre orientation angle as typical process parameters. GRA is adopted to obtain grey relational grade for the milling process with multiple characteristics, namely, machining force and material removal rate (MRR). Analysis of variance is performed to get the contribution of each parameter on the performance characteristics.

It is observed that helix angle and fibre orientation angle are the most significant process parameters that affect the milling of GFRP composites. The experimental results reveal that the helix angle of 45°, spindle speed of 3000 rpm, feed rate of 1000 mm/min, depth of cut of 2 mm and fibre orientation angle of 15° is the optimum combination of lower machining force and higher MRR. The experimental results for the optimal setting show that there is considerable improvement in the process.

Optimization of process parameters on machining force and MRR during endmilling of GFRP composites using GRA has not been attempted previously.

This study investigates the brand selfies that have the capability to help brands thrive through crises. The brand selfies spark a self-inferential process that makes customers feel connected to the brand and makes them biased toward a specific brand during an uncertain situation.

A total of 166 questionnaires were analyzed through structural equation modelling (Smart PLS) and a niche group of young millennials from Thailand was selected based on their luxury items usage, frequency of visits to leisure spas and hotels, expensive car showrooms, branded jewelry stores and luxury watch shops.

The study highlights the emergence of brand selfies during the crisis and the priority given by customers as compared to brand-generated content or promotional campaigns. The results indicated a positive influence of brand selfies on brand preferences directly and through the mediation of brand signature.

It is fascinating for brands that customers voluntarily include their products in their carefully crafted and staged selfies that deliver their image and massages as social signifiers during a chaotic situation.

The research classifies the impacts of brand selfies in the luxury, leisure and tourism market of Thailand and its assistance in thriving through crises. The study is one of the rare studies that present brand selfies as a hassle-free promotional tool for brand signature and a game-changing strategy to deal with crises.