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The high availability of solar energy in the Gulf Cooperation Council (GCC) makes it the most attractive source of energy in this region, especially due to the global shift toward eco-friendly systems. A significant increase in the implementation of solar PV projects has been noticed in the United Arab Emirates (UAE). For this reason, this study conducted a multi-criteria decision-making process to compare four locations for building a solar PV park in the UAE, namely, Abu Dhabi, Dubai, Sharjah, and Umm Al Quwain. Various criteria were taken into account, including the solar radiation, wind speed, distance from the electricity grid, distance from seaports, and land cost. A hybrid AHP-TOPSIS model was employed to evaluate the criteria weights and alternatives' scores, which were also compared with the no priority-TOPSIS to check the effects of the criteria weights on the overall ranking. According to the findings, Dubai and Abu Dhabi were ranked first and second, with final scores of 0.7108 and 0.4427, respectively, when using the AHP-TOPSIS model. Furthermore, Umm Al Quwain scored slightly less than that of second place, with a value of 0.4252. The top two ranked alternatives were consistent between the two compared models, as Dubai also performed the best among all locations, which confirmed the reliability of the proposed approach and verified the obtained results and rankings. [ABSTRACT FROM AUTHOR]

Recently, there have been several advancements in the field of sustainable energy solutions, particularly in the selection of solar window film sheets. In this research, a multi-criteria decision-making approach was applied to compare three different types of window film sheets, Silver 35, TrueVue 15, and Sterling 40, to aid in selecting the most suitable window film based on the United Arab Emirates market. The primary aim of this work is to provide decision-makers with a structured approach to enhance their choices for selecting window film sheets. The methodology employed involves evaluating various criteria, including visible light transmittance, solar energy rejected, energy transmittance, energy absorptance, cost, glare reduction, visible light reflectance interior, and fade reduction. These criteria are assessed using the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The results demonstrate that Sterling 40 is the best choice followed by Silver 35. Based on the final TOPSIS results, the difference between the scores of these two window film sheets was not significant, while they were far from the score of TrueVue 15. [ABSTRACT FROM AUTHOR]

This comprehensive review examines various methods of treating medical waste in the context of the sustainable development goals (SDGs). A bibliometric analysis was conducted to investigate the impact of COVID‐19 on medical waste, which showed a notable increase in publications in recent years. Findings indicate that thermal treatment with energy recovery, including pyrolysis, gasification, oxidation, and plasma gasification, is the most effective approach for managing medical waste. However, research on the impacts of medical waste on SDGs is insufficient, warranting further investigations to better understand the intersections between medical waste management and the SDGs. The need for international cooperation and collaboration in addressing medical waste management challenges, especially during crises, is highlighted. Understanding the links between medical waste management and the SDGs is crucial in developing sustainable solutions aligned with the global sustainability agenda. Further research and international collaboration are needed to address the challenges associated with medical waste management and contribute to the achievement of the SDGs. [ABSTRACT FROM AUTHOR]

Daylight can contribute to substantial reductions in the energy consumed by artificial lighting applications. However, issues such as visual comfort, illumination intensity, and availability represent major issues when daylight is relied upon to illuminate buildings. There are many technologies that are used to control received sunlight and minimize its side effects. The placement of solar film sheets on window glass is a common and popular method utilized in many buildings to minimize electric lighting energy consumption without causing undue visual discomfort to occupants. To examine the practicality of this application and its effect on room lighting, a modern office was selected in which to conduct this field study. Two measures were used to evaluate this technique: firstly, field measurements and their comparison to the specified standard illumination levels; and secondly, a short-form questionnaire survey conducted to obtain occupants' opinions of the office lighting. Actual measurements were conducted in the selected office spaces, with and without applying solar control film coating on the window glass. Indoor luminance levels and lighting comfort were systematically recorded and analyzed. The findings of this study show that using a solar film with a visible light transmittance of 50% can achieve savings in energy consumption of up to 33% if utilized as part of an integrated lighting system. [ABSTRACT FROM AUTHOR]

The amount of energy that a thermoelectric generator (TEG) is capable of harvesting mainly depends on the temperature difference between the hot and cold sides of the TEG. To ensure that the TEG operates efficiently under any condition or temperature variation, it is crucial to have a reliable MPPT that keeps the TEG as close as possible to its MPP. Fractional control is usually preferred over integer control because it allows for more precise, flexible, and robust control over a system. The controller parameters in fractional control are not limited to integer values, but rather can have fractional values, which enables more precise control of the system's dynamics. In this paper, an optimized fractional PID-based MPPT that effectively addresses two primary issues, dynamic response and oscillation around MPP, is proposed. Firstly, the five unknown parameters of the optimized fractional PID-based MPPT were estimated by the BES "bald eagle search" algorithm. To validate the superiority of the BES, the results were compared with those obtained using other optimization algorithms, such as ant lion optimizer (ALO), equilibrium optimizer (EO), cuckoo search (CS), and WOA "whale optimization algorithm". The results demonstrate that BES outperforms ALO, EO, CS, and WOA. Additionally, the tracking performance of proposed MPPT was evaluated using two scenarios that involved variations in temperature differences and sudden changes in the load demanded. Overall, the proposed optimized fractional PID-based MPPT effectively improves dynamic performance and eliminates oscillation around MPP under steady state compared to other tracking methods, such as P&O "perturb and observe" and incremental conductance (INR). [ABSTRACT FROM AUTHOR]

Recently, water desalination (WD) has been required for the supply of drinking water in a number of countries. Various technologies of WD utilize considerable thermal and/or electrical energies for removing undesirable salts. Desalination systems now rely on renewable energy resources (RERs) such as geothermal, solar, tidal, wind power, etc. The intermittent nature and changeable intensity constrain the wide applications of renewable energy, so the combination of energy storage systems (ESSs) with WD in many locations has been introduced. Thermal energy storage (TES) needs a convenient medium for storing and hence reuses energy. The present work provides a good background on the methods and technologies of WD. Furthermore, the concepts of both thermal and electrical energy storage are presented. In addition, a detailed review of employing ESSs in various WD processes driven by RERs is presented. The integration of energy storage with water desalination systems (WDSs) based on renewable energy has a much better capability, economically and environmentally, compared with conventional desalination systems. The ESSs are required to guarantee a constant supply of fresh water over the day. [ABSTRACT FROM AUTHOR]

The rapid growth in fossil fuels has resulted in climate change that needs to be controlled in the near future. Several methods have been proposed to control climate change, including the development of efficient energy conversion devices. Fuel cells are environmentally friendly energy conversion devices that can be fuelled by green hydrogen, with only water as a by-product, or by using different biofuels such as biomass in wastewater, urea in wastewater, biogas from municipal and agricultural wastes, syngas from agriculture wastes, and waste carbon. This editorial discusses the fundamentals of the operation of the fuel cell, and their application in various sectors such as residential, transportation, and power generation. [ABSTRACT FROM AUTHOR]

The use of fossil fuels has contributed to climate change and global warming, which has led to a growing need for renewable and ecologically friendly alternatives to these. It is accepted that renewable energy sources are the ideal option to substitute fossil fuels in the near future. Significant progress has been made to produce renewable energy sources with acceptable prices at a commercial scale, such as solar, wind, and biomass energies. This success has been due to technological advances that can use renewable energy sources effectively at lower prices. More work is needed to maximize the capacity of renewable energy sources with a focus on their dispatchability, where the function of storage is considered crucial. Furthermore, hybrid renewable energy systems are needed with good energy management to balance the various renewable energy sources' production/consumption/storage. This work covers the progress done in the main renewable energy sources at a commercial scale, including solar, wind, biomass, and hybrid renewable energy sources. Moreover, energy management between the various renewable energy sources and storage systems is discussed. Finally, this work discusses the recent progress in green hydrogen production and fuel cells that could pave the way for commercial usage of renewable energy in a wide range of applications. [ABSTRACT FROM AUTHOR]

In this study, a green hydrogen system was studied to provide electricity for an office building in the Sharjah emirate in the United Arab Emirates. Using a solar PV, a fuel cell, a diesel generator, and battery energy storage; a hybrid green hydrogen energy system was compared to a standard hybrid system (Solar PV, a diesel generator, and battery energy storage). The results show that both systems adequately provided the power needed for the load of the office building. The cost of the energy for both the basic and green hydrogen energy systems was 0.305 USD/kWh and 0.313 USD/kWh, respectively. The cost of the energy for both systems is very similar, even though the capital cost of the green hydrogen energy system was the highest value; however, the replacement and operational costs of the basic system were higher in comparison to the green hydrogen energy system. Moreover, the impact of the basic system in terms of the carbon footprint was more significant when compared with the green hydrogen system. The reduction in carbon dioxide was a 4.6 ratio when compared with the basic system. [ABSTRACT FROM AUTHOR]

Heat pipe systems have attracted increasing attention recently for application in various heat transfer-involving systems and processes. One of the obstacles in implementing heat pipes in many applications is their difficult-to-model operation due to the many parameters that affect their performance. A promising alternative to classical modeling that emerges to perform accurate modeling of heat pipe systems is artificial intelligence (AI)-based modeling. This research reviews the applications of AI techniques for the modeling and control of heat pipe systems. This work discusses the AI-based modeling of heat pipes focusing on the influence of chosen input parameters and the utilized prediction models in heat pipe applications. The article also highlights various important aspects related to the application of AI models for modeling heat pipe systems, such as the optimal AI model structure, the models overfitting under small datasets conditions, and the use of dimensionless numbers as inputs to the AI models. Also, the application of hybrid AI algorithms (such as metaheuristic optimization algorithms with artificial neural networks) was reviewed and discussed. Next, intelligent control methods for heat pipe systems are investigated and discussed. Finally, future research directions are included for further improving this technology. It was concluded that AI algorithms and models could predict the performance of heat pipe systems accurately and improve their performance substantially. [ABSTRACT FROM AUTHOR]

In this paper, a modified bald eagle search optimization algorithm was applied for the first time to determine the parameters of the triple diode model (TDM) of perovskite solar cells (PSCs). Two experimental datasets are considered; the first is measured I–V points for a PSC at standard conditions. The second consists of the measured I–V points for a modified PSC. In contrast, the cost function to be minimized is the root mean square error (RMSE) between the experimental dataset and the calculated one. To prove the superiority of modified bald eagle search optimization (mBES), a comparison with the original bald eagle search optimization (BES), particle swarm optimizer (PSO), Hunger games search (HGS), and recent Coronavirus Disease Optimization Algorithm (COVIDOA) was implemented. Furthermore, statistical analysis of ANOVA and Tukey tests was performed. The results demonstrate the lead of the recommended mBES in identifying the parameters of the TDM for PSCs, where the RMSE achieved the least value among the used optimization algorithms in this study. [ABSTRACT FROM AUTHOR]

Adsorption heat storage is the most feasible technology for heating decarbonization, which can store large quantities of waste and renewable heat for an exceptionally long time. However, utilizing adsorption heat storage in geographical locations with sub-zero ambient conditions is challenging. Therefore, this paper experimentally investigates the use of ethanol as a working fluid paired with silica gel for adsorption heat storage and utilizes sub-zero ambient as the heat source. The heat storage characteristics, heat charging/discharging cyclic performance, and energy conversion performance via exergy analysis were determined under realistic operating conditions and benchmarked against the widely investigated silica gel/water. Ethanol adsorbate was successfully utilized as a working fluid to employ the evaporators operating under sub-zero ambient conditions. Silica gel/ethanol showed the most significant net cyclic uptake, twice that of silica gel/water. However, the physical characteristics of ethanol molecules led to a degree of non-desorbed fluid, which hampered such potential to store 18.08 kJ/kgads under a sub-zero evaporator temperature and 24.84 kJ/kgads for an above-zero evaporator temperature compared to silica gel of 155.12 kJ/kgads operating an above-zero evaporator temperature. On the other hand, silica gel/ethanol showed the fastest heat charging/discharging rate that can shorten the cycle time by 45%. The major contributor to exergy destruction was the exergy transferred by charging heat, which was five times the discharging heat due to the high charging temperature. [ABSTRACT FROM AUTHOR]

The use of solar thermal systems (STSs) has recently reached a significant edge. The increasing research on developing an alternative power supply for limiting fossil fuel usage and climate change are the driving forces of STSs. The current work explores the recent progress in STSs' applications, including PV/T or "photovoltaic/thermal" systems, zero-energy buildings, greenhouse solar thermal applications, solar thermal for pumping water, solar thermal refrigerators, solar chimneys, water desalination, and solar collectors, along with the benefits and challenges of these applications. Then, the potential contribution of STSs in achieving the various SDGs or "Sustainable development goals", including barriers and research gaps, are elaborated. In brief, STSs significantly contribute to the seventeen SDGs' achievement directly and indirectly. Recent developments in the engineering applications of STSs are strongly based on the materials of construction, as well as their design, process optimisation, and integration with multidisciplinary sciences and technologies such as modelling, nanoscience/nanotechnology, and artificial intelligence. [ABSTRACT FROM AUTHOR]

Summary: Amoxicillin is a pharmaceutical pollutant that has severe impacts on aquatic life. Traditional treatment methods of Amoxicillin contaminated wastewater are expensive and inefficient. This paper uses soft computing to identify the best operating parameters of the solar photocatalysis process. The target is to maximize the degradation of Amoxicillin from wastewater. The proposed methodology integrates ANFIS modelling and grey wolf optimization (GWO). Three operating parameters are considered: TiO2 (g/L) dosage, initial antibiotic concentration (mg/L), and initial pH to maximize the AMX degradation (%). Based on experimental datasets, ANFIS model is designed to simulate the output solar photocatalysis process in terms of the mentioned operating parameters. The constructed ANFIS model is accurate; the R‐squared values are 0.9982 and 0.9979 for training and testing. Then, using GWO, the best values of TiO2 (g/L), Amoxicillin (mg/L), and pH are determined. The results were compared with an optimized performance by response surface methodology and experimental data to demonstrate the superiority of the suggested methodology. The suggested methodology maximized the Amoxicillin (AMX) degradation by 3% while using higher initial AMX concertation by 60% and 90%, compared with the experimental and RSM methodologies. The results demonstrated the superiority of the proposed method in determining the adequate operating conditions while keeping the same operating conditions of the applied pH and TiO2 concentration. [ABSTRACT FROM AUTHOR]

Fuel cells (FCs) have received huge attention for development from lab and pilot scales to full commercial scale. This is mainly due to their inherent advantage of direct conversion of chemical energy to electrical energy as a high-quality energy supply and, hence, higher conversion efficiency. Additionally, FCs have been produced at a wide range of capacities with high flexibility due to modularity characteristics. Using the right materials and efficient manufacturing processes is directly proportional to the total production cost. This work explored the different components of proton exchange membrane fuel cells (PEMFCs) and their manufacturing processes. The challenges associated with these manufacturing processes were critically analyzed, and possible mitigation strategies were proposed. The PEMFC is a relatively new and developing technology so there is a need for a thorough analysis to comprehend the current state of fuel cell operational characteristics and discover new areas for development. It is hoped that the view discussed in this paper will be a means for improved fuel cell development. [ABSTRACT FROM AUTHOR]

Geothermal Energy is a very attractive source of naturally-occurring green renewable energy. Exploiting this natural resource is straightforward and causes almost no ill effects to the environment. But, while geothermal does not suffer the intermittence of other renewable sources, its extraction efficiency is fairly modest as compared to other sources. As a result, there has been significant interest recently in hybrid systems that integrate geothermal and other forms of energy to increase the output efficiency. This work will survey the different possible integrations involving geothermal energy. A review of the literature shows that the most common hybrid systems implementation involve the integration of geothermal with solar (45% of systems) followed by the integration of a cooling tower into the geothermal system (30% of systems). This work will also investigate the applications for geothermal hybrids and show that 44% of systems are designed for heating applications. Another 44% are used for cooling while only 12% are designed for electrical power generation. Complexity of control remains as the main obstacle facing hybrid multi-source energy systems including those involving geothermal energy. Image 1 • Hybrid geothermal systems (HGS) have low initial and operating costs. • HGSs can supply all types of energy demands and decrease the effect of peak loads. • HGSs reduce negative environmental impact of energy systems. [ABSTRACT FROM AUTHOR]

This study aims to analyze the determinants that influence the consumers' disposition to invest in microgrid technology in the United Arab Emirates (UAE). This research offers valuable insights for policymakers on investors' motivations to develop strategies to foster microgrid technology adoption through end-user investments leading to a reduction in microgrid high capital cost. The study employed descriptive statistics, correlation, and regression analyses to analyze the responses of a sample of property owners to a quantitative survey. The study examines such variables as strategic alignment, profitability, digitization, renewable energy utilization, CO2 emission reduction, and disaster recovery readiness. The data collected reveal a moderate level of understanding and cost-awareness of microgrid technology among the respondents, with a mean of 2.46 out of 5. Notably, the data highlight the significant influence of strategic alignment with the UAE's national energy goals on the respondents' inclination to invest in microgrids, with a strong positive correlation of 0.942 at the 0.01 level (two-tailed). By comparison, profitability and disaster recovery have a comparatively weaker correlation. Furthermore, based on the data collected during this study, it has been determined that there is a strong value added by the microgrid initiatives considering the UAE's strategic direction and the positive influence of reduced CO2. The regression models used were highly significant at F = 85.690. There is an acceptable level of multicollinearity with VIF values ranging from 1.087 to 2.155. UAE Strategy has low collinearity. UAE Strategy emerges as the only significant predictor of willingness to invest (p < 0.001) in the stepwise regression analysis. The analysis shows that villa and townhouse owners are willing to invest in community microgrid given that it is aligned with UAE strategy and leads to CO2 emissions reduction. [ABSTRACT FROM AUTHOR]

This research paper presents a comprehensive review of the literature on microgrid development in the UAE, focusing on the socio-economic costs and benefits, policy frameworks, market dynamics, and environmental implications. The analysis encompasses publications from 2011 to 2021, with a particular emphasis on the United Arab Emirates (UAE) and the Gulf Cooperation Council (GCC) countries. A total of 33 papers were identified and classified, revealing gaps in comprehensive valuation models, consideration of environmental and social governance factors, and research informing policy and investment decisions. The findings highlight the significance of microgrid technology in the UAE, its limited adoption and commercialization, and its predominant usage in remote areas and academic testbeds. The paper underscores the UAE's vision for net-zero emissions by 2050 and the potential of microgrids in supporting its realization. Recommendations include the development of a comprehensive valuation framework to drive effective investments in microgrid technology, aligning with the UAE's sustainable energy goals. The study contributes to the understanding of microgrid development in the UAE, offering insights into its socio-economic, policy, market, and environmental dimensions. [ABSTRACT FROM AUTHOR]

• Three designs of photovoltaic-based skylights are proposed to save energy in buildings. • The integration of vacuum glazing with photovoltaic skylights is evaluated. • Using a vacuum layer at the backside of the PV layer is favorable for thermal insulation. • Using a vacuum-based PV skylight reduces the total U-value from 6.3 to 1.9 W/m2.K at ASTM. • Using the vacuum layer with the PV-skylight slightly decreases the power generation of the PV. In commercial buildings with large glazing facades, transparent facades and skylights play a considerable impact on energy consumption. In this study, three different photovoltaic (PV) -based skylights are compared to save energy in these buildings. The first skylight uses a vacuum glazing sample as a substrate at the backside of the PV layers. The second design integrates a vacuum glazing layer in front of the PV layers. And lastly, the PV layers are attached to a single layer of glazing with a solar cells covers 25% of the whole area. A 3D thermal model is developed and validated with data from the literature to compare these designs. it is concluded that using a vacuum layer at the backside of the PV layer is favorable for thermal insulation and attains relatively similar power generation to the case without a vacuum layer. In more detail, replacing the single glazing PV skylight with the first skylight design reduces the total U-value of the glazing from 6.3 to 1.9 W/m2.K for a glazing sample with an area of 0.4 m by 0.4 m at ASTM boundary conditions. Furthermore, at received solar irradiance of 1000 W/m2, an ambient temperature of 25 °C, and a wind speed of 1 m/s, replacing the third skylight design with the first skylight design slightly reduced the electricity generation from 37.4 W/m2 to 36.4 W/m2, significantly decreased the heat flux transfer from 91.1 W/m2 to 50.5 W/m2 and lowers the indoor surface temperature from 32.1 °C to 27.1 °C. [ABSTRACT FROM AUTHOR]

Historically, technological advancements in rechargeable batteries have been accomplished through discoveries followed by development cycles and eventually through commercialisation. These scientific improvements have mainly been combination of unanticipated discoveries and experimental trial and error activities. However, with the increased complexity of rechargeable battery systems and diversification in ever-demanding new applications requires a strategical approaches to commercialise newly developed battery chemistries. This can only be achieved by fast-tracking the transfer of key finding from scientific laboratories to industrial collaborators in order to design commercially feasible devices. Despite the dominance of lithium-ion batteries (LiBs) commercially in current rechargeable battery market which ranges from small scale applications such as portable electronic devices to large scale applications including transportation to grid scale electrical energy storage. Scientific community is endeavouring to consolidate the global rechargeable battery portfolio with the alternative rechargeable battery systems based on cost-effective, safe, and environmentally friendly battery chemistries. This brief prospective will provide an update on the historical developments, current technological scenario and future expectations, current and potential applications, and challenges faced by current and future rechargeable battery technology. • Brief overview working principle of different rechargeable battery systems. • Technological progression of rechargeable battery technology. • Challenges face by current battery technology. • Current and emerging applications of rechargeable batteries. [ABSTRACT FROM AUTHOR]

• NiCo-CNC@C nanoarchitectures are successfully prepared. • NiCo-CNC@C electrode is highly advantageous for supercapacitors. • NiCo-CNC@C electrode displays a specific capacity of 194.8 mAh/g at 1 A/g. • HSCs cell demonstrates specific energy of 72.6 Wh kg−1 at specific power of 1780 W kg−1. The family of transition metal carbides (TMCs) has been rapidly expanded since the discovery of the Ti 3 C 2 MXenes for various energy-orientated applications. The metal-like electronic conductivity of TMCs is suitable for getting the high-power capability for the energy storage system. However, the practical applications of TMCs are still overwhelming owing to their poor redox activity and limited energy-storing capacity. Herein, a highly conductive yet redox-active metallic nickel–cobalt intertwined cobalt–nickel carbide@carbon (NiCo-CNC@C) nanoarchitecture cathode was developed for the high-performance hybrid supercapacitor. Experimental analysis reveals that the incorporation of metals in metal carbide enhances the electronic states, minimizes the barriers in reaction kinetics, and improves redox-active species, thus boosting electrochemical performance. Accordingly, the obtained NiCo-CNC@C-700 with optimized material composition presents a high specific capacity of 194.8 mAh/g at 1 A/g with exceptional rate capability (76.8 % at 20 A/g). Moreover, a hybrid solid-state supercapacitor assembled with NiCo-CNC@C-700 and WO 3 @C as positive and negative electrodes delivers a specific energy density of 72.6 Wh kg−1 at specific power of 1780 W kg−1 and superior cycle stability. The proposed approach of metals blended with metal carbides proves their feasibility by regulating the redox reactivity of materials to encompass their practices in upcoming energy storage applications. [ABSTRACT FROM AUTHOR]

Supercapacitors are considered comparatively new generation of electrochemical energy storage devices where their operating principle and charge storage mechanism is more closely associated with those of rechargeable batteries than electrostatic capacitors. These devices can be used as devices of choice for future electrical energy storage needs due to their outstanding performance characteristics. Based on their performance, supercapacitors can be placed somewhat in middle of rechargeable batteries and conventional electrostatic capacitors since supercapacitors have higher energy and power densities when compared with electrostatic capacitors and rechargeable batteries respectively. Supercapacitors have seen increased use recently as stand-alone as well as complementary devices along with other energy storage systems such as electrochemical batteries. Therefore, it is believed that supercapacitors can be a potential alternative electrochemical energy storage technology to that of widely commercialised rechargeable batteries especially lithium-ion batteries. In this brief prospective, authors have attempted to present an overview of the evolution of supercapacitor technology and its current/future applications. • Technological evolution of supercapacitors has been covered. • Supercapacitor has been evaluated as an energy storage device. • Classification of supercapacitors has been discussed. [ABSTRACT FROM AUTHOR]

This special issue is dedicated to the research presented and discussed at the 8th International Conference on Sustainable Energy & Environmental Protection held from the 11th to the 14th August 2015 in Paisley, Scotland. The contents of this special issue are within the aims and scope of Renewable and Sustainable Energy Reviews. The aim of the International conferences on Sustainable Energy & Environmental Protection is to gather experts, practitioners and early career researchers together in a relaxed environment to present their research findings. The articles published in this special issue summarise a snapshot of the diverse range of topics from bioenergy and biogas, energy storage and district heating and energy in buildings to carbon emissions, carbon flux in soil and social aspects of carbon discussed at the conference within the framework of sustainable development. A total of eighteen extended manuscripts were invited by for consideration for publication following the conference and after a robust review process by experts in the field a total of ten articles were accepted. [ABSTRACT FROM AUTHOR]

Metal–air batteries are a promising technology that could be used in several applications, from portable devices to large-scale energy storage applications. This work is a comprehensive review of the recent progress made in metal-air batteries MABs. It covers the theoretical considerations and mechanisms of MABs, electrochemical performance, and the progress made in the development of different structures of MABs. The operational concepts and recent developments in MABs are thoroughly discussed, with a particular focus on innovative materials design and cell structures. The classical research on traditional MABs was chosen and contrasted with metal–air flow systems, demonstrating the merits associated with the latter in terms of achieving higher energy density and efficiency, along with stability. Furthermore, the recent applications of MABs were discussed. Finally, a broad overview of challenges/opportunities and potential directions for commercializing this technology is carefully discussed. The primary focus of this investigation is to present a concise summary and to establish future directions in the development of MABs from traditional static to advanced flow technologies. A systematic analysis of this subject from a material and chemistry standpoint is presented as well. [ABSTRACT FROM AUTHOR]

To meet the increasing energy demand, renewable energy is considered the best option. Its patronage is being encouraged by both the research and industrial community. The main driving force for most renewable systems is solar energy. It is abundant and pollutant free compared to fossil products. Wind energy is also considered an abundant medium of energy generation and often goes hand in hand with solar energy. The last few decades have seen a sudden surge in wind energy compared to solar energy due to most wind energy systems being cost effective compared to solar energy. Wind turbines are often categorised as large or small depending on their application and energy generation output. Sustainable materials for construction of different parts of wind turbines are being encouraged to lower the cost of the system. The turbine blades and generators perform crucial roles in the overall operation of the turbines; hence, their material composition is very critical. Today, most turbine blades are made up of natural fiber-reinforced polymer (NFRP) as well as glass fiber-reinforced polymer (GFRP). Others are also made from wood and some metallic materials. Each of the materials introduced has specific characteristics that affect the system's efficiency. This investigation explores the influence of these materials on turbine efficiency. Observations have shown that composites reinforced with nanomaterials have excellent mechanical characteristics. Carbon nanotubes have unique characteristics that may make them valuable in wind turbine blades in the future. It is possible to strengthen carbon nanotubes with various kinds of resins to get a variety of different characteristics. Similarly, the end-of-life treatment methods for composite materials is also presented. [ABSTRACT FROM AUTHOR]

Photovoltaic-thermal (PVT) technologies have demonstrated several attractive features, such as higher power and comparative efficiencies. Improving the thermal recovery from the PVT system would further improve the power output and the efficiency of the PVT system. This paper identifies the best operating factors of nanofluid-based PV thermal/nano-enhanced phase change material using artificial intelligence. The target is the maximization of thermal energy and exergy outputs. The suggested approach combines ANFIS modelling and particle swarm optimization (PSO). Four operating factors are taken into consideration: PCM (phase change material) layer thickness, HTF (heat transfer fluid) mass flow rate, MFNPCM ("mass fraction of nanoparticles in PCM") and MFNfluid ("mass fraction of nanoparticles in nanofluid"). Using a dataset, an "adaptive neuro-fuzzy inference system" (ANFIS) model has been established for simulating the thermal energy and exergy outputs in terms of the mentioned operating factors. Then, using PSO, the best values of PCM thickness, mass flow rate, MFNPCM and MFNfluid are estimated. The proposed model's accuracy was examined by comparing the results with those obtained by response surface methodology and the experimental dataset. [ABSTRACT FROM AUTHOR]

This review presents a detailed summary of the latest technologies used in flywheel energy storage systems (FESS). This paper covers the types of technologies and systems employed within FESS, the range of materials used in the production of FESS, and the reasons for the use of these materials. Furthermore, this paper provides an overview of the types of uses of FESS, covering vehicles and the transport industry, grid leveling and power storage for domestic and industrial electricity providers, their use in motorsport, and applications for space, satellites, and spacecraft. Different types of machines for flywheel energy storage systems are also discussed. This serves to analyse which implementations reduce the cost of permanent magnet synchronous machines. As well as this, further investigations need to be carried out to determine the ideal temperature range of operation. Induction machines are currently stoutly designed with lower manufacturing cost, making them unsuitable for high-speed operations. Brushless direct current machines, the Homolar machines, and permanent magnet synchronous machines should also be considered for future research activities to improve their performance in a flywheel energy storage system. An active magnetic bearing can also be used alongside mechanical bearings to reduce the control systems' complications, thereby making the entire system cost-effective. [ABSTRACT FROM AUTHOR]

A typical assumption when performing analytical, numerical, and experimental studies in wave–structure interaction in multi-body problems such as for wave farms and very large floating structures is the homogeneity of the wave field. Important interactions between the floating elements are dependent on the direction, amplitude, and phase of the waves acting on each. Then, wave homogeneity is probably unrealistic in near-shore areas where these installations are to be deployed. In the present work, an existing interaction method, which allows the use of standard boundary element diffraction codes for solving the first order wave structure linear potential for each unique geometry in the problem, is shown to be able to account for inhomogeneous sea states across the domain of a multi-body problem requiring only minimal modification to its implementation. A procedure to use the method to include arbitrary incoming undisturbed wave conditions at each body is presented. A verification study was done by using an artificial numerical configuration to mimic an inhomogeneous wave field in a standard diffraction code, which was used as a reference. The results obtained using the interaction-method based procedure are shown to be in excellent agreement with the reference ones. Furthermore, an example of frequency inhomogeneity of the wave field in a wave farm is shown and the effects on the motion amplitudes and absorbed power are presented illustrating the applicability of the procedure. [ABSTRACT FROM AUTHOR]

The growing energy demands has led to a soaring level of greenhouse gas (GHG) production, with the implementation of EU legislations, the production of GHG and waste is being curbed but with an economic disadvantage. Multiple industries face losing their competitive edge due to the restrictions currently in place due to the inability to readily burn fossil fuels. With developments of thermal and physical waste management, multiple companies are utilising waste heat technologies to recapture previously lost energy to be used in other applications. The spectrum of papers in this special issue can be split into two main themes recovering energy to be used in other applications such as waste heat recovery applications and thermoacoustic engines and energy conversion via pyrolysis. Such technologies featured in the special edition reflect the growing need for a solution to reduce the production of greenhouse gases but also lower the level of global warming. [ABSTRACT FROM AUTHOR]

This paper introduces a comprehensive overview of various graphene production and deposition processes with a main focus on their utilization for energy harvesting and augmentation applications. A focused view on simple yet effective mechanical exfoliation techniques to produce graphene, and sometimes simultaneously deposit it. Two of these techniques, i.e. ball milling technique and compressed air blasting of graphite have been used and developed in our labs, respectively. The produced and deposited graphene via these methods is tested for energy harvesting enhancement in applications such as the spectral absorption enhancement of solar thermal collectors, electrode production for capacitive deionization, and as Nano-spacers in SERS applications for solar PV cells with an increase in 28% compared with Pt-based counterelectrode. The two mechanical production processes of graphene discussed are facile, economical and rapid, and is expected to bring solid-state graphene production a step closer to automation, a concept that is currently synonymous only with solution-based processes. These processes enabled the incorporation of a graphene layer on solar thermal collectors and this layer has exhibited 43% enhancement in efficiency than ones that did not have a graphene layer. Because of graphene eminence and its well-established place in many areas one of them being energy this is due to its unique thermal, mechanical, optical, electronic, and chemical properties. This paper will analyze the tools used for the synthesis of graphene and their throughput, cost and ease of use. [ABSTRACT FROM AUTHOR]

In this study we investigated the potential use of coffee waste feedstock in biodiesel production, considering economic viability, technical feasibility, and environmental compatibility. The investment potential for a small-scale biodiesel production facility (8000 t/y) was gauged by estimating relevant economic performance indicators. Biodiesel was then extracted from spent coffee grounds and blended with fossil diesel to develop four blends: B5, B10, B15, and B20. The conformity of this fuel with relevant standards (ASTM D6751 and ISO EN14214) was determined by characterizing and adjusting the fuel's properties during the production process. The technical and environmental performance of these blends was then tested in a single-cylinder compression ignition engine with an extended range of engine speeds under three engine loading conditions (100%, 75%, and 50%), using pure diesel fuel for benchmark comparisons. The evaluated economic metrics paint an optimistic picture of investment in this project. Waste coffee could result in improved economic performance over other feedstocks. Diesel fuel outperformed the biodiesel blends in terms of engine power, thermal efficiency, and fuel economy, whereas the blends were superior in terms of exhaust gas temperature; average exhaust gas temperature drops of 11 °C and 35.2 °C were measured under full load conditions for B5 and B20, respectively. All blends emitted lower levels of CO 2 , CO, and HC than did diesel, but higher NOx emissions were present, all proportional to the blend used. Our results clearly show that SCG has great potential as a feedstock for biodiesel production, given its derivation from existing waste materials, cleaner but comparable performance, and economically viable production. • Spent coffee grounds (SCG) are a potential feedstock for biodiesel production. • SCG are an existing waste product requiring no further cultivation for fuel production. • Economic analysis of an 8000 t/y plant indicated potential for financial viability. • Technical analysis showed that SCG biodiesel performs comparably to regular diesel. • Tailpipe emissions of CO, CO 2 , and HC were lower (NOx was higher) for SCG biodiesel. [ABSTRACT FROM AUTHOR]

Quantum dots are semiconductor nanoparticles containing a range of materials with a core-shell structure. They receive discernible attention in today's world due to their potential applications, from energy storage devices to medical applications. Nevertheless, there are many approaches to their synthesis and stability routes. This review focuses on two approaches for the synthesis of quantum dots, namely surface functionalization and quantum dot doping. In addition, their stability routes were discussed, such as the intermediate shell approach, alloyed core/shell approach, shell thickness approach, ligand design approach, and over-coating approach. The review concludes by addressing the recent progress of quantum dots applications, notably in photocatalysis for different applications, such as cathode, anode, and membranes for fuel cell applications, solar cells, sensors, and various energy storage devices applications. • QDs are characterized by their tunable size, composition, and fluorescence features. • Functionalization and doping of QDs are the main remarkable achievements in synthesis. • The stability of QDs can be enhanced by following the core-shell structure. • QDs can be stabilized by the intermediate shell approach, alloyed core/shell approach, and overcoating approach. [ABSTRACT FROM AUTHOR]

With the growing demand for green technologies, hydrogen energy devices, such as Proton Exchange Membrane (PEM) fuel cells and water electrolysers, have received accelerated developments. However, the materials and manufacturing cost of these technologies are still relatively expensive which impedes their widespread commercialization. Additive Manufacturing (AM), commonly termed 3D Printing (3DP), with its advanced capabilities, could be a potential pathway to solve the fabrication challenges of PEM parts. Herein, in this paper, the research studies on the novel AM fabrication methods of PEM components are thoroughly reviewed and analysed. The key performance properties, such as corrosion and hydrogen embrittlement resistance, of the additively manufactured materials in the PEM working environment are discussed to emphasise their reliability for the PEM systems. Additionally, the major challenges and required future developments of AM technologies to unlock their full potential for PEM fabrication are identified. This paper provides insights from the latest research developments on the significance of advanced manufacturing technologies in developing sustainable energy systems to address the global energy challenges and climate change effects. • The AM technologies relevant to PEM fabrication are reviewed. • Corrosion performance of AM materials in the PEM working environment is presented. • The challenges and prospects of AM for PEM fabrication are discussed. • AM has the potential to revolutionize the fabrication of PEM systems. [ABSTRACT FROM AUTHOR]

There are numerous reports and publications in reputable scientific and engineering journals that attribute substantial enhancement in heat transfer capabilities for heat exchangers once they employ nanofluids as working fluids. By definition, a nanofluid is a working fluid that has a small volume fraction (5% or less) of a solid particle with dimensions in the nanoscale. The addition of this solid material has a reported significant impact on convective heat transfer in heat exchangers. This work investigates the significance of the reported enhancements in many recent related publications. Observations on these publications' geographical origins, fundamental heat transfer calculations, experimental setups and lack of potential applications are critically made. Heat transfer calculations based on methodologies outlined in random selection of available papers were conducted along with a statistical analysis show paradoxically inconsistent conclusion as well as an apparent lack of complete comprehension of convective heat transfer mechanism. In some of the surveyed literature for example, heat transfer coefficient enhancements were reported to be up to 27% and 48%, whereas the recalculations presented in this work restrain proclaimed enactments to ~ 3.5% and − 4% (no enhancement), respectively. This work aims at allowing a healthy scientific debate on whether nanofluids are the sole answer to enhancing convective heat transfer in heat exchangers. The quantity of literature that confirms the latter statement have an undeniable critical mass, but this volition could be stemming from and heading to the wrong direction. Finally, the challenges imposed by the physical nature of nanoparticles, as well as economic limitations caused by the high price of conventional nanoparticles such as gold (80$/g), diamond (35$/g), and silver (6$/g) that hinder their commercialization, are presented. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFCs) are promising form of energy conversion technology that have the potential to take the role of lithium-ion batteries in portable electronics and electric cars. To increase the efficiency of DMFCs, many operating conditions ought to be optimized. Developing a reliable fuzzy model to simulate DMFCs is a major objective. To increase the power output of a DMFC, three process variables are considered: temperature, methanol concentration, and oxygen flow rate. First, a fuzzy model of the DMFC was developed using experimental data. The best operational circumstances to increase power density were then determined using the beetle antennae search (BAS) method. The RMSE values for the fuzzy DMFC model are 0.1982 and 1.5460 for the training and testing data. For training and testing, the coefficient of determination (R2) values were 0.9977 and 0.89, respectively. Thanks to fuzzy logic, the RMSE was reduced by 88% compared to ANOVA. It decreased from 7.29 (using ANOVA) to 0.8628 (using fuzzy). The fuzzy model's low RMSE and high R2 values show that the modeling phase was successful. In comparison with the measured data and RSM, the combination of fuzzy modeling and the BAS algorithm increased the power density of the DMFC by 8.88% and 7.5%, respectively, and 75 °C, 1.2 M, and 400 mL/min were the ideal values for temperature, methanol concentration, and oxygen flow rate, respectively. [ABSTRACT FROM AUTHOR]

Thin-walled structures are frequently used as energy absorbers in the automotive, railway and aviation industries. This paper addresses the crashworthiness performance of thin-walled windowed tubes under dynamic impact loading. Different shapes of cut-outs were introduced to thin-walled tubes with different cross-sectional shapes to create windowed tubes. Explicit finite element code, LS-DYNA, was used to simulate the crushing behaviour of the windowed tubes under axial impact loading. The Finite Element (FE) model was validated by conducting experimental tests and showing that the numerical and experimental responses are comparable. The crashworthiness responses of the different windowed tubes were compared and the best performing tube was identified using a multi-criteria decision-making method known as Technique of Order Preference by Similarity to Ideal Solution (TOPSIS). It was found that a circular tube with a square window shape outperforms all other sections and exhibits the best energy absorption characteristics. Subsequently, a multi-objective optimisation analysis was performed to find the optimal configuration of the best tube. Response Surface Methodology (RSM) was used to develop models for the energy absorption responses of the tube. The design variables were selected to describe size, number, and distributions of the windows, while specific energy absorption (SEA) and peak crush force (PCF) were set as design responses. Parametric analysis was conducted to understand the effects of the design variables on the crashworthiness behaviour and the optimal configuration was identified. • The axial crushing behaviour of different simple and windowed tubes was investigated. • Crashworthiness performances of the different tubes were compared and the best tube was identified. • Response surface method and desirability approach were used to optimise the best performing tube. [ABSTRACT FROM AUTHOR]

This paper models two strategic decisions made by industrial entities: the intention to adopt a renewable energy system (RES) and the timeframe for this adoption. The methodology presented considers multiple layers of "unobserved heterogeneity." The results of random parameters imply that the parameters exhibit unobserved heterogeneity across industrial entities. For example, high non-electric energy costs increase the probability of selecting a shorter timeframe in 81.8% of entities and reduce that probability in 18.2% of entities. The results of this study also show that the majority (60%) of responding entities intend to adopt an RES within a short timeframe, generally one to two years, while 40% intend to adopt an RES three or more years after 2022. According to our findings, green bank loans, electricity tariffs, the type of industry, government bureaucracy, and entities' export capabilities predominantly influence their intention to adopt an RES. The results also show that energy-intensiveness (e.g., industrial entities in the plastic and rubber, food and drinks, and chemicals and paints sectors), high electricity tariffs, and elevated non-electric energy costs often expedite the adoption process (resulting in shorter adoption timeframes). Government impediments tend to cause entities to delay their adoption decisions. Capital costs are by far the largest impediment to adoption, as indicated by 29.3% of the surveyed entities, followed by government legislation at 18.6%. The findings presented offer crucial knowledge for creating opportunities to implement new policies and produce an environment in which industries can expedite their transitions to renewable energy. • Solar PV demand by the industrial sector is addressed through heterogeneity models. • Two key decisions are addressed: the intention to adopt and the adoption timeframe. • Heterogeneity in means and variances of the random parameters are accounted for. • Several explanatory variables turned out to influence the two demand decisions. • Heterogeneity models are statistically superior to fixed parameters models. [ABSTRACT FROM AUTHOR]

Cobalt oxide, nickel oxide and cobalt/nickel binary oxides were synthesised by electrodeposition. To fine tune composition of CoNi alloys, growth parameters including voltage, electrolyte pH/concentration and deposition time were varied. These produced nanomaterials were used as binder free electrodes in supercapacitor cells and tested using three electrode setup in 2 MKOH aqueous electrolyte. Cyclic voltammetry and galvanostatic charge/discharge were used at different scan rates (5–100 mV/s) and current densities (1–10 A/g) respectively to investigate the capacitive behaviour and measure the capacitance of active material. Electrochemical impedance spectroscopy was used to analyse the resistive/conductive behaviours of these electrodes in frequency range of 100 kHz to 0.01 Hz at applied voltage of 10 mV. Binary oxide electrode displayed superior electrochemical performance with the specific capacitance of 176 F/g at current density of 1 A/g. This hybrid electrode also displayed capacitance retention of over 83% after 5000 charge/discharge cycles. Cell displayed low solution resistance of 0.35 Ω along with good conductivity. The proposed facile approach to synthesise binder free blended metal electrodes can result in enhanced redox activity of pseudocapacitive materials. Consequently, fine tuning of these materials by controlling the cobalt and nickel contents can assist in broadening their applications in electrochemical energy storage in general and in supercapacitors in particular. [ABSTRACT FROM AUTHOR]

There are numerous reports and publications in reputable scientific and engineering journals that attribute substantial enhancement in heat transfer capabilities for heat exchangers once they employ nanofluids as working fluids. By definition, a nanofluid is a working fluid that has a small volume fraction (5% or less) of a solid particle with dimensions in the nanoscale. The addition of this solid material has a reported significant impact on convective heat transfer in heat exchangers. This work investigates the significance of the reported enhancements in many recent related publications. Observations on these publications' geographical origins, fundamental heat transfer calculations, experimental setups and lack of potential applications are critically made. Heat transfer calculations based on methodologies outlined in random selection of available papers were conducted along with a statistical analysis show paradoxically inconsistent conclusion as well as an apparent lack of complete comprehension of convective heat transfer mechanism. In some of the surveyed literature for example, heat transfer coefficient enhancements were reported to be up to 27% and 48%, whereas the recalculations presented in this work restrain proclaimed enactments to ~ 3.5% and − 4% (no enhancement), respectively. This work aims at allowing a healthy scientific debate on whether nanofluids are the sole answer to enhancing convective heat transfer in heat exchangers. The quantity of literature that confirms the latter statement have an undeniable critical mass, but this volition could be stemming from and heading to the wrong direction. Finally, the challenges imposed by the physical nature of nanoparticles, as well as economic limitations caused by the high price of conventional nanoparticles such as gold (80$/g), diamond (35$/g), and silver (6$/g) that hinder their commercialization, are presented. [ABSTRACT FROM AUTHOR]

Over the past several decades, a noticeable amount of research efforts has been directed to minimising injuries and death to people inside a structure that is subjected to an impact loading. Thin-walled (TW) tubular components have been widely employed in energy absorbing structures to alleviate the detrimental effects of an impact loading during a collision event and thus enhance the crashworthiness performance of a structure. Comprehensive knowledge of the material properties and the structural behaviour of various TW components under various loading conditions is essential for designing an effective energy absorbing system. In this paper, based on a broad survey of the literature, a comprehensive overview of the recent developments in the area of crashworthiness performance of TW tubes is given with a special focus on the topics that emerged in the last ten years such as crashworthiness optimisation design and energy absorbing responses of unconventional TW components including multi-cells tubes, functionally graded thickness tubes and functionally graded foam filled tubes. Due to the huge number of studies that analysed and assessed the energy absorption behaviour of various TW components, this paper presents only a review of the crashworthiness behaviour of the components that can be used in vehicles structures including hollow and foam-filled TW tubes under lateral, axial, oblique and bending loading. [ABSTRACT FROM AUTHOR]

The world is moving towards renewable energies as an alternative to fossil fuels. The photovoltaic technologies have the highest capacity increase rate among all the renewable energy systems throughout the last decade. Therefore, the huge amounts of photovoltaic wastes from such significant global installations are inevitable and needs to be dealt with sooner than later to increase the potential of PVs being an affordable and clean energy source. This work is split into two parts with different models. The first one mathematically models the PV waste projection using the Weibull distribution and socio-environmental decision-making factors while connecting them to the power purchase agreements (PPAs). This model uses data from both c-Si and CdTe PV projects in the United Arab Emirates (UAE). This model's results showed the possibility of increasing the PV projects operational age in UAE to 30 years for both technologies with 2030 being the best and latest year to start PV waste management procedures with the profitable reusability of PVs after projects' decommissioning. The second part is an optimization model for the PV waste and installations management by controlling the total future PV installations and possible PV replacements, while considering budget limitations and dismantling capacities. With a planning horizon until the year of 2100, this model's results suggest annually installing 670 MW of new PVs to achieve 50% of the country's consumption by 2030 and 100% by 2040 without any power shortage or outage. Finally, the models are flexible and extremely beneficial for future works for improvements, results comparison, and to design PV waste management centers or dismantling facilities. • Projected PV wastes through socio-environmental factors and Weibull distribution. • Built an optimization model to balance PV installations with waste replacements. • Unprecedently improved both c-Si and CdTe PV waste management plans in the UAE. • Install 670 MW of PVs annually to achieve 50% of the country's consumption by 2030. • Required annual replacements will start exceeding 100 MW by 2040. [ABSTRACT FROM AUTHOR]

An experimental and numerical investigation on the thermal and mechanical response of a lined pipe (compound pipe) under welding is presented. The welding process consists of a single-pass overlay welding (inner lap-weld) and a two-pass girth welding (outer butt-weld). The influence of the filler material of the girth welding has been examined thermally and mechanically as it is a key factor that can affect the quality of lined pipe welding. To this end, a three-dimensional non-linear finite element model based on the ABAQUS code has been developed and successfully validated against small-scale experimental results. This study was conducted on two specimens of lined pipe joined together by a girth welding deposited either by mild steel or by austenitic stainless steel. Furthermore, in this study, a pre-heat treatment required to produce lined pipe specimens has been taken into account. Strains and residual stresses have been measured by means of high temperature strain gauges, residual stress gauges and the X-ray diffraction technique along the inner and outer surfaces of the welded lined pipe whereas the thermal history has been recorded by thermocouples. The findings point out that replacing the girth welding mild steel by austenitic stainless steel has a significant effect on the residual stress results but no influence on the thermal history results. Two identical welded lined pipes connected by single-pass weld overlay and two-pass girth welding, dimensions in mm. [Display omitted] • The temperature fields are not affected by changing the girth welding material. • Replacing the girth welding to austenitic stainless steel shorten the length of residual plastic strain on the outer surface. • Beyond the fusion zones, the residual stresses are not influenced by changing the girth welding material. [ABSTRACT FROM AUTHOR]

Massive expansions in the global population and the global digitalization throughout the industrial revolution are causing energy security issues that are no longer environmentally affordable through conventional power generation systems. As an alternative solution, the global power capacities and production of the renewable energy systems in general and the photovoltaic technologies in particular, are significantly increasing every year. With a lifetime range of 25–40 years, the PV power plants will eventually and over their lifetime or cumulatively turn into large masses of waste. This work briefly reviews the market state of the three generations of PV and summarizes their most recent technical challenges. It is highlighted that the c-Si (Crystalline Silicon) and CdTe (Cadmium Telluride) technologies have a relatively high level of market maturity, least number of technical challenges, and most interesting space for sustainable development. Furthermore, a one-of-a-kind sustainable and circular PV industry's business model was developed, to directly and indirectly address the practical business and engineering gaps concerning environmental, economic, social, and technical factors affecting the circular transition of the PV industry. The model assisted in reviewing and discussing articles concerning material compositions, manufacturing processes, and dismantling processes. Previous reviews and surveys reported the lack of dedicated PV dismantling facilities and miscommunications between the supply chain stages and logistics. Therefore, a critical review was done on the most recent and comprehensive articles related to the optimizations and improvements of the PV industry's sustainability towards the anticipated circular economy. Additionally, this work highlights the objectives, key constraints, and major strategies of the sustainability's environmental, economic, and social pillars within the photovoltaic industry and business stages, which introduced the possible contributions of the industry 4.0 technologies. Therefore, a brief section was dedicated to the possible utilizations of Industry 4.0 throughout the critical stages of the photovoltaics' economy. Finally, a research road map was developed to assist all levels of future researches in optimizing the PV's circular economy and the overall sustainability of the industry. [Display omitted] • Market states, potentials, and challenges of the three generations of PV were discussed. • Crystalline silicon- and CdTe- based technologies are the dominating source of PV wastes. • A circular business model was developed for the PV industry. • Recent improvements and optimizations towards sustainable PV lifecycle were critically discussed. • A novel research roadmap is created to assist in future research on PV's circular economy. [ABSTRACT FROM AUTHOR]

Graphene is fundamentally a two-dimensional material with extraordinary optical, thermal, mechanical, and electrical characteristics. It has a versatile surface chemistry and large surface area. It is a carbon nanomaterial, which comprises sp2 hybridized carbon atoms placed in a hexagonal lattice with one-atom thickness, giving it a two-dimensional structure. A large number of synthesis techniques including epitaxial growth, liquid phase exfoliation, electrochemical exfoliation, mechanical exfoliation, and chemical vapor deposition are used for the synthesis of graphene. Graphene prepared using different techniques can have a number of benefits and deficiencies depending on its application. This study provides a summary of graphene preparation techniques and critically assesses the use of graphene, its derivates, and composites in environmental applications. These applications include the use of graphene as membrane material for the detoxication and purification of water, active material for gas sensing, heavy metal ions detection, and CO2 conversion. Furthermore, a trend analysis of both synthesis techniques and environmental applications of graphene has been performed by extracting and analyzing Scopus data from the past ten years. Finally, conclusions and outlook are provided to address the residual challenges related to the synthesis of the material and its use for environmental applications. [ABSTRACT FROM AUTHOR]

In recent years, many researchers have been conducted on batteries' health monitoring and prognostics, mainly focusing on the batteries' state of charge (SOC). Accurately estimating the state of health (SOH) and predicting the remaining useful life (RUL) of battery components are very important for the prognosis and health management of the overall battery system. However, due to the non-linear dynamics caused by the electrochemical characteristics in batteries, the accurate estimations of SOC, SOH and RUL prediction are still challenging and many technologies have been developed to solve this challenge. This paper reviews and discusses state of the art in SOC and SOH and RUL estimation techniques for all battery types. A novel framework is developed and presented to compare all battery techniques based on three dimensions: battery performance (Z dimension), approaches (X dimension), and criteria (Y dimension) to fulfil. All studies are reviewed and discussed based on the dimensions and the criteria defined in the framework. Based on this investigation, this study summarizes at the end the key outcomes and suggests future research challenges. Novel framework for battery monitoring and prognostics optimization techniques comparison. [Display omitted] • Batteries' health monitoring and prognosis. • Predicting the battery service life. • Techniques for battery health monitoring and management. • Framework to compare all battery techniques based on the performance and the criteria to fulfil. [ABSTRACT FROM AUTHOR]

Recent studies have reported improved biogas and methane yield from marine biomass when the particle size is mechanically reduced and the specific surface area available to enzymes is increased prior to anaerobic incubation. Although the advantage of reducing the particle size has been identified, an ideal particle size that would offer greater yield with a positive energy balance has not been identified for such substrate to date. As particle size reduction by mechanical means is often highly demanding in energy, this paper attempts to fill this gap for macroalgal biomass by identifying the particle size distribution allowing the highest biogas and methane yields obtained in a previous work. The study estimated that when about 80% of the particles are sized below 1.6 mm 2 , a biogas and methane yield improvement of up to 52% and 53% respectively can be achieved. The results are discussed in relation to the biogas yield, related methane content and potential inhibitory phenomena occurred during the fermentation. [ABSTRACT FROM AUTHOR]