Abstract In this study, a new type of oxycarbide-based compounds, namely lanthanum titanium oxycarbide and neodymium titanium oxycarbide, were synthesized through solid-state reaction to replace titanium oxycarbide due to its rapid charge carrier recombination and limited responsiveness to visible light (VL) in photocatalysis. The structural, morphological, optical absorption, and vibrational properties of the synthesized catalysts were thoroughly characterized using powder X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy to assess their suitability for catalytic applications. Subsequently, the photocatalytic behavior of the synthesized materials was evaluated for their ability to degrade the hazardous Congo red (CR) dye in various types of water, including deionized water, domestic utility water used for household purposes, and seawater, under VL illumination. Notably, lanthanum titanium oxycarbide and neodymium titanium oxycarbide exhibited superior degradation efficiencies for CR dye, achieving maximum degradation rates of 87% and 89%, respectively, in domestic water used for routine household purposes within a duration of 90 minutes, when compared to TiOC. However, the degradation efficiency was slightly lower in deionized water and seawater. Additionally, lanthanum titanium oxycarbide and neodymium titanium oxycarbide demonstrated promising hydrogen evolution activity, generating 19.7 and 21.1 µmol/g, respectively, under VL in 180 minutes. The enhanced efficiency in CR removal and hydrogen generation activity of lanthanum titanium oxycarbide and neodymium titanium oxycarbide has been attributed to the synergistic effects of improved VL absorption, higher exciton separation and a supportive pH environment due to the presence of lanthanum, neodymium, and carbon ions in a combined entity.

Abstract The continuous rise in CO2 emissions from fossil fuel consumption has intensified the search for alternative clean energy sources. Hydrogen produced from renewable sources like ethanol offers a promising alternative to fossil fuels, mitigating CO2 emissions. This study investigates the kinetics of hydrogen production via ethanol steam reforming using a nickel-based catalyst, specifically the Ar-401 catalyst. Characterization techniques, including scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller method, temperature-programmed reduction, and powder X-ray diffraction, were used to analyze the catalyst properties. Under optimal conditions of 973 K, atmospheric pressure, and a steam-to-ethanol ratio of 9, we achieved 100% ethanol conversion, 74.8% hydrogen selectivity, and 85% hydrogen yield. Kinetic experiments were conducted under kinetically controlled conditions, examining the effects of temperature (473–673 K) and weight hourly space velocity ranging from 1 to 15 (g·h/mol). A power law kinetic model was developed, yielding an activation energy of 11.17 kJ/mol and a reaction order of 0.46, with an absolute average deviation of 3.23% between predicted and experimental rates. This study provides key insights into the reaction mechanisms and highlights the effectiveness of the nickel-based catalyst, providing valuable insights for the design of efficient chemical reactors for sustainable hydrogen production.

This chapter explores the concept of solar-integrated hydrogen production, a promising method for generating clean fuel using renewable energy. It delves into the various techniques for splitting water into hydrogen and oxygen using solar energy, including photovoltaic–electrochemical (PV-EC), photoelectrochemical (PEC), and solar thermochemical approaches. This chapter analyzes the current challenges faced by this technology, such as efficiency limitations, material costs, and system complexity. Finally, it discusses recent advancements and ongoing research efforts focused on improving efficiency, scalability, and cost-effectiveness, paving the way for the widespread adoption of solar-integrated hydrogen production as a key component of a sustainable energy future.

Besides ensuring food security, the agriculture sector provides livelihood to 8.4 million people in India. The advent of the Green Revolution in India not only increased food production and improved livelihoods for many, but it also had detrimental consequences on the environment. Intensive agriculture techniques such as the use of agrochemicals have significantly affected the health and resilience of agroecosystems. Degraded soil quality significantly affects crop yields, while poor management of agro-waste poses threats to air quality and human health. Therefore, it is essential to promote sustainable farming practices that prioritize environmental protection along with improved productivity. The use of biochar in the agriculture sector has gained attention due to its wide range of applications, including pollution control, climate change mitigation, and soil improvement. Carbon in biochar is highly recalcitrant and can be stored in the soil for long periods, promoting soil fertility. Biochar also helps build organic carbon in soil and reduces carbon emissions associated with the production and use of mineral fertilizers. Furthermore, it enables the sustainable use of waste biomass that would otherwise generate high concentrations of methane and carbon dioxide through open burning or natural decomposition. Upcycling agro-residue to biochar is a promising technique for waste management and enhancing the effectiveness of the circular economy.

The urban heat island (UHI) effect leads to an increase in the ambient temperature of urban areas, significantly impacting the built environment. As a direct result of increased heat, the cooling load of buildings increases, leading to higher energy demand. One of the key strategies to reduce this impact of UHI is the creation of the urban blue–green infrastructure (UBGI) networks, which act as nature-based solutions. This study presents a methodological framework to delineate a strategically located UBGI network for Varanasi city and estimates the potential reduction in building cooling energy demand. The study uses geographical information system and remote sensing to spatially locate the UBGI network and a quantified cooling factor to calculate the potential reduction in cooling demand. The urban area is divided into sub-watersheds, depicting primary drainage channels. UBGI elements are delineated based on urban morphology and available land of the respective sub-watershed. The green areas delineated in this way represent an optimal land-suitability scenario where blue and green areas sustain each other. As a result, these delineated UBGI networks show a reduction in building cooling energy demand of 2.1%–20.3%. The study, thus, validates the importance of UBGI in mitigating the negative impacts of UHI and contributed to the creation of more climate-resilient and sustainable cities.

Urbanization is the newest trend of the 21st century, pacing rapidly and affecting cities’ living standards, growth, and infrastructure. Considering the increasing need for research on several factors affecting the urban climate, analysis of socially active areas, particularly the green areas in urban regions, has become significantly important for urban planners. Urban green space (UGS) is essential for minimizing air pollution, preventing climate change, and offering a variety of ecosystem services. One of the challenges posed by urbanization is land allocation priorities for urban green cover. Hence, safeguarding urban trees is essential for ensuring the future of inclusive and sustainable cities. This chapter is an exploratory study on UGSs, that is, to enhance the existing UGSs and to optimize the planning of green spaces, an inclusive evaluation of the current condition, issues, and potentials must be conducted. Fifteen of the 17 United Nations Sustainable Development Goals can be accomplished through well-organized planning of green spaces in urban areas. The central focus of this study is to understand UGSs in four major cities in central India. The parameters considered are total geographical area, demography, per capita UGS, decadal change in spatial patterns, and the average temperature of cities. This chapter critically reflects on the lacunas and the effect of green areas in controlling average temperatures, thereby reducing the urban heat island (UHI) effect in urban areas.

Abstract Yttrium barium copper oxide (YBCO) is used for special applications in linear generators because of its excitation loss, lower weight, and higher efficiency. These qualities enable the compound to operate better than the conventional copper wire coil in the stator unit of the linear generator. However, the continuous use of YBCO in linear generators has a fundamental challenge that affects industrial production and material stability after prolonged use. This paper seeks to sustain the adoption of YBCO by improving its quality for linear generator applications. The yttrium cuprates modification (YBYbCO) was synthesized using the solid-state reaction technique by doping YBCO with ytterbium. The crystalline structure, microstructural pattern, and stability of the new sample were adequately measured and found to be structurally stable to ensure durability. It was reported that applying YBYbCO in the linear generator would lead to a 200% increase in energy generation. The higher number of particles and lower individual particulate resistance enable it to withstand chemical pressure, thereby prolonging the lifespan of the linear generator.

Abstract Integrating small and large-scale photovoltaic (PV) solar systems into electrical distribution systems has become mandatory due to increased electricity bills and the concern for limiting greenhouse gases. However, the reliable and efficient operation of PV-based distribution systems can be confronted by the intermittence and high variability of solar sources and their consequential faults. In this regard, this article suggests a moderated fault-clearing strategy based on the incremental conductance–maximum power point tracking (IC–MPPT) technique and artificial neural networks (ANNs) to enhance fault detection, localization, and restoration processes in PV-based distribution systems. The proposed strategy leverages IC–MPPT to ensure optimal power generation from the PV solar system, even in the presence of faults. By tracking the maximum power point, the algorithm maintains the performance of the system and mitigates against the impact of faults on the output power. Furthermore, an ANN is employed to improve fault detection and localization accuracy. The developed ANN-based moderated fault-clearing strategy is trained using historical data and fault scenarios, enabling it to recognize fault patterns and make informed decisions through extensive simulations and comparisons with traditional fault-clearing methods. To accomplish this study, benchmarks in PV-based distribution systems are constructed and employed using the MATLAB®/Simulink® software package. Moreover, to validate the efficacy of the developed ANN-based moderated fault-clearing strategy, a real case study of a 1-MW PV-based distribution system in an industrial field located in Giza governorate, Egypt, is tested and investigated. The obtained results demonstrate the effectiveness of the IC–MPPT and ANN-based moderated fault-clearing strategy in achieving faster fault detection, precise fault localization, and efficient restoration in PV solar-based distribution systems while preserving maximum power extraction under small and large system disturbances. Furthermore, IC–MPPT based on an ANN achieves an average power of 98.556 kW and 299.632 kWh energy availability, whereas the IC–MPPT based on a proportional–integral controller achieves 95.7996 kW and 283.4036 kWh, and the classic perturb-and-observe MPPT algorithm achieves 92.2657 kW and 276.8014 kWh.

Abstract Social acceptance is a challenging aspect that affects the development of geothermal energy and such issues have been reported in many countries, such as Germany, Japan, Greece, and Kenya. In this study, we discuss the barriers to social acceptance and associated risks faced by geothermal energy developers in East Africa. We have conducted semi-structured interviews with international organizations (38.5%), public companies (38.5%), and private companies (23.1%). The interviews were qualitatively analysed using inductive content analysis. The key barriers identified by respondents were the lack of political, market, and community awareness; lack of local political support; lack of public funding; human resource shortages; involuntary resettlement; local cultural aspects; employment issues; and demographic change. The lack of awareness of geothermal energy affects public and private funding, and leads to negative risk perception by communities. Risks, such as air, soil, and water pollution, land acquisition, social exclusion, resource risks, and drilling and project costs, were considered important by our respondents. In this study, we emphasize the need for the following: raising awareness regarding geothermal energy; training professionals; implementing strong surface studies to reduce the risks associated with the exploration stage; and conducting environmental and social impact assessment reports to mitigate negative risks to local communities, while also ensuring their engagement and raising their awareness about the negative risks of geothermal energy.

Abstract The performance of photovoltaic modules is affected by environmental factors such as irradiance and temperature, which can lead to a decrease in output performance or even damage. This study proposes an improved formula for calculating the real maximum power of photovoltaic modules by analyzing the influence of irradiance and temperature. A simulation model is developed using PLECS software to simulate the global maximum power of photovoltaic modules under different environmental conditions, and the results are compared with the calculated real maximum power. A power optimization scheme for photovoltaic modules is then proposed based on current equalization and constant voltage control. This scheme employs a single-switch multi-winding forward-flyback converter to equalize the mismatched currents between cell strings, thereby enhancing the output performance. Traditional proportional integral controllers are utilized to achieve constant voltage control and obtain the real maximum power of photovoltaic modules. Simulation models are built in the PLECS simulation platform to evaluate the performance of a global maximum power point tracking scheme based on the traditional perturb and observe algorithm with current equalization, a segment perturb and observe algorithm without current equalization, and the proposed power optimization scheme. The simulation results demonstrate that the proposed constant voltage control has greater efficiency than the traditional perturb and observe algorithm. The proposed scheme achieves a significant improvement in efficiency, with a 27.87% increase compared to the segment perturb and observe algorithm without current equalization.