This paper proposes a hybrid structure for multi-stream large-scale multi-input multi-output (MIMO) beamforming systems, in single-user scenario, using a Hadamard radio frequency (RF) codebook with low-bit resolution phase shifters. We show that Hadamard transform can be used in RF beamsteering/beamcombining to achieve better performance in terms of average achievable spectral efficiency and low hardware cost using 1- or 2-b resolution APSs. In contrast, the state-of-the-art RF codebook designs available in the literature requires more than 7-b resolution to achieve the same performance as the proposed scheme, for large antenna arrays with up to 256 elements. The performance gains of the proposed RF codebook design is thoroughly investigated using MATLAB simulations for typical mmWave MIMO system, and the simulation results are closely verified by the analytical expressions.

Universal filtered multi-carrier (UFMC) is a potential multi-carrier system for future cellular networks. UFMC provides low latency, frequency offset robustness, and reduced out-of-band (OOB) emission that results in better spectral efficiency. However, UFMC suffers from the problem of high peak-to-average power ratio (PAPR), which might impact the function of high power amplifiers causing a nonlinear distortion. We propose a comparative probabilistic PAPR reduction technique, called the decomposed selective mapping approach, to alleviate PAPR in UFMC systems. The concept of this proposal depends on decomposing the complex symbol into real and imaginary parts, and then converting each part to a number of different phase vectors prior to the inverse fast Fourier transform (IFFT) operation. The IFFT copy, which introduces the lowest PAPR, is considered for transmission. Results obtained using theoretical analysis and simulations show that the proposed approach can significantly enhance the performance of the UFMC system in terms of PAPR reduction. Besides, it maintains the OOB emission with candidate bit error rate and error vector magnitude performances.

Wind power plants have emerged as a cornerstone in the global effort to transition toward renewable energy sources, offering a clean and sustainable solution for electricity generation. This review paper provides a comprehensive analysis of technological advancements, efficiency optimization strategies, and challenges faced by the wind energy sector. Modern wind turbines have evolved significantly, with innovations such as larger rotor diameters (up to 220 meters) and increased tower heights (reaching 160 meters) that enhance energy capture. These design improvements have boosted turbine capacity, with new models achieving power outputs of up to 15 MW per turbine, compared to 2-3 MW for earlier designs, leading to a 30-40% increase in efficiency. Offshore wind farms, benefiting from consistent and stronger winds, demonstrate higher capacity factors, averaging around 45-60%, compared to 30-35% for onshore farms. The introduction of floating wind turbines has expanded offshore installations into deeper waters, where winds are more reliable, further increasing the overall efficiency of wind energy systems. Advanced materials such as carbon fiber composites have reduced turbine weight, enhancing both durability and performance. Moreover, integrating AI and smart technologies has led to a 20-25% reduction in maintenance costs through predictive maintenance and optimization algorithms that adjust blade angles and turbine orientation in real-time. Despite these advancements, challenges persist. Wind intermittency and variability remain critical issues, with capacity utilization rates often below 50%. Engineers address this challenge through energy storage solutions, including battery systems, which have shown up to 80% efficiency in managing supply-demand fluctuations.

Diesel engine power plants play a critical role in the global energy landscape, offering reliable and flexible power generation solutions. With thermal efficiencies ranging from 35% to 45%, these plants outperform traditional gasoline engines and provide substantial energy output, with specific fuel consumption rates between 200 and 250 g/kWh. However, their operation poses significant sustainability challenges, particularly regarding greenhouse gas emissions and air quality. Diesel engines emit approximately 0.15 to 0.2 kg of CO2 per kWh, contributing to climate change, while nitrogen oxides (NOx) emissions can reach up to 20 g/kWh, necessitating advanced emission control technologies to meet regulatory standards. Furthermore, the extraction and transportation of diesel fuel can lead to environmental degradation and habitat loss. As the world transitions towards cleaner energy sources, the sustainability of diesel power plants is under scrutiny, prompting the need for strategies that enhance their efficiency while minimizing their ecological footprint. Integrating renewable energy technologies, implementing carbon capture methods, and optimizing operational practices are crucial steps to align diesel power generation with global sustainability goals.

The integration of commercial fuel additives in diesel engine generator systems presents a viable and cost-effective strategy for enhancing operational efficiency, reducing harmful emissions, and lowering maintenance costs in power plants. This study investigates the role of different fuel additives, including cetane improvers, detergents, lubricity enhancers, and emission reducers, in optimizing the performance of diesel engines. By improving fuel combustion, increasing fuel system cleanliness, and reducing engine wear, these additives can significantly boost the overall efficiency of power generation systems. Quantitative analysis shows that fuel additives can lead to a 2-5% improvement in fuel efficiency, primarily due to more complete combustion and better fuel utilization. Lubricity enhancers further protect critical engine components from wear, extending equipment lifespan and minimizing operational downtime, while detergents prevent the buildup of deposits in fuel injectors, ensuring consistent and optimal fuel atomization. A notable example of these benefits can be seen in a diesel-powered plant in India, where the use of commercial fuel additives resulted in a 4% increase in fuel efficiency, alongside a 15% reduction in NOx emissions and cleaner engine operation. Despite initial costs associated with the adoption of fuel additives, the long-term savings from enhanced fuel economy, reduced emissions penalties, and lower maintenance costs offer considerable financial and environmental benefits. In conclusion, the use of commercial fuel additives can play a crucial role in improving the sustainability and operational performance of diesel engine power plants, contributing to the global shift toward cleaner energy solutions.