• First generation biofuel has the highest biofuel yield and energy efficiency. However, the production of the biofuel opposed many sustainable development goals.

• Third and fourth generation biofuels show potential as a sustainable future green energy.

• Methods of lipid extraction of microalgae biofuel and environmental consequences of the fourth generation biofuel should be further explored.

Offshore wind energy conversion (OWEC) has attracted intensive attentions due to its significant advantages in sufficient wind energy, high power output and low land occupancy rate. This article firstly introduces the state-of-the-art of the development status of the offshore wind energy technology worldwide, and then comprehensively analyzes the advantages and constraints of the OWEC technology. Finally, the future development trend of the offshore wind energy is envisioned.

This study aims to establish a performance evaluation method to advance the appropriate design for multistage indirect evaporative cooling systems. Theoretical analysis has been carried out by using a validated mathematical model. The values of performance evaluation criteria were calculated to study the combined influence on the cooling effectiveness, the pressure drop, and the cooling capacity.

• The effectiveness of combining S type and H type on a counter-rotating VAWT has been studied.
• The new combined design was able to enhance the performance of the system significantly and was able to operate in a low-speed wind condition.
• An average power coefficient and torque coefficient of up to 30% and 42% were, respectively, achieved using this technique.

This paper proposes a new way to recover intermediate waste epoxy resins. Mixing with fir is able to make the alternative fuel homogeneous after torrefaction. The emissions during co-torrefaction and co-combustion are detected by FTIR.

Novelty

• Functionally graded metal foam heat sink has been designed for CPV.
• A CFD model has been developed to investigate the performance of the functionally grade metal foam.
• Optimized pore density and porosity of the functionally graded metal foam have been identified.

The integration of BBPS in the iron manufacturing enabled a negative carbon emission. An 80% reduction of carbon footprint upper threshold target allowed an improvement of the negative carbon footprint by 34.15% while enhancement on the annualized capital cost of 1.81% was achieved. The influence in the change in biomass price is relatively significant compared with the change in the iron ore and coal prices.

All the existing H₂O/IL working fluids are studied for absorption cooling cycles; this study aims to screen the suitable H₂O/IL working fluids for ATES. The major merit of using H₂O/ILs as novel ATES working fluids is that the solutions can be charged to be more concentrated while staying away from crystallization risk. In this manner, the ATES has higher reliability without crystallization and higher ESDs with enlarged concentration differences.

• Fractal structure of hexagonal fins is imposed to a minichannel for enhancing heat transfer with a moderate pressure penalty.

• Laminar convection is enhanced by diffluence and confluence flows in the fractal channel due to strong flow mixing and thermal boundary layer redevelopment.

• Heat transfer enhanced by hexagonal fins outweighs its pressure penalty.

• The optimum branching angle and the relative hexagonal side length can be evaluated by the performance factor.

A three-step optimization design method was adopted to a practical engineering. It is more economical to use heat pump central heating system in severely cold regions. The operating control equation of heat pump central heating system was obtained.

By 2025, the demand of lithium for chargeable and nonchargeable batteries is expected to reach 212 000. Therefore, the safety of an electric vehicle largely depends on the mechanical characteristics of its battery pack. In addition, a lighter weight electric vehicle has longer driving range, which makes it much more popular in vehicle market. In this paper, a comprehensive procedure based on finite element analysis is applied to compare the maximum equivalent stress, total deformation, and resonance frequency on a battery pack casing with different materials under parking, bumpy road, sharp turns, and sudden braking conditions to obtain the best material. Although aluminum 6061 is tested to have lower maximum equivalent stress, carbon nanotubes (CNT) is proved to be the best material considering all of these three performance standards. Then, response surface optimization design method is adopted to get an optimal design of the battery pack casing. Optimization results concluded that the maximum equivalent stress can be reduced from 3.9243 to 3.2363 MPa, and the six-order resonance frequency can be increased from 722.65 to 1040.751 Hz.

• Blended nanomorphologies of Ag/SiO₂ for concentrating volumetric solar energy.
• Silica shell is transparent to the visible and near-infrared radiation bands.
• Silica shell consolidates the intensity of the LSPR and the absorption characteristics.
• A stable, high absorption efficiency low concentration nanofluid has been suggested.
• The DASC efficiency can reach 75% for a solar concentration ratio of 50.

Monk fruit seed was synthesized into heterogeneous acid catalyst for biodiesel production using 2-steps surface functionalization with phenylation and sulfonation method. Effects of synthesis and reaction parameters for esterification were investigated and biodiesel yield up to 98.5% was successfully obtained. In addition, the characterizations done on the as-synthesized catalysts proved that the synthesis process successfully modified the catalyst's structure. The catalyst was also highly robust which could maintain 84.4% biodiesel yield up to 4 successive cycles.

Isotropic and anisotropic thermal conductivities of the four lithium-ion batteries with different positive electrodes are reviewed. The maximum temperature and temperature difference of the battery employing isotropic and anisotropic thermal conductivities are approximately the same. Obvious differences are observed in temperature distributions of the battery employing isotropic and anisotropic thermal conductivities. Thermal conductivity bounds of lithium-ion batteries are established to check the reliability of the thermal conductivity data used in battery thermal models.

• Three-dimensional packed-sphere model for rock-soil thermal conductivity prediction.

• The parallel thermal resistance method was applied to solve the model.

• Prediction results validation with the measurement values of three groups of rock-soil.

• Application range and prediction accuracy analysis.

A macroscale curved channel with periodical wave structure is proposed for enhancing heat transfer rate with a moderate pressure drop. The mechanism of the heat transfer enhancement is analyzed based on the local surface Nusselt number and the secondary flow. The heat transfer enhancement can be mainly attributed to the periodical thermal entrance effect along the flow direction.

Schematic of the experimental procedure to predict the discharge capacity/life of Li-ion batteries.

• This article suggests an alternative heat spreading material for effective thermal management in light-emitting diode packaging system.
• In this study, magnesium oxide thin films were deposited on aluminum substrate and used as heat spreader in-between light-emitting diode and heat sink. High thermal conductivity was recorded from the magnesium oxide thin film, low thermal resistance, low thermal impedance, and high illumination that were obtained from the light-emitting diode mounted on the magnesium oxide thin films.

Low thermal impedance and low thermal resistance for effective heat spreading: appreciable film thickness and high thermal conductivity from magnesium oxide thin film prove the thin film as an alternative heat spreading material in light-emitting diode packaging system towards improvement of thermal path for excessive heat removal from the package to the ambient.

This is a pilot study of building-integrated photovoltaics at Heriot-Watt University Malaysia, which proposes an optimized configuration covering both technical and economic assessments. The novel methodology approach involves 3D modelling of the building geometry, which provides a variety of interactive graphics for decision-making. The modelling focuses on tilt and orientation factor (TOF) for unconventional subject surfaces, which is the curved roofs. The work adopts realistic weather data that provides reliable energy yield estimation, losses, performance ratio, and payback time.

A schematic diagram of the double flash-binary geothermal power plant with lithium extraction column.

• A robust Adaptive Network-based Fuzzy Inference System (ANFIS) model for methane production from waste paper was built using fuzzy logic modelling based on the experimental datasets.
• A particle swarm optimizer (PSO) was used to maximize methane production through optimizing beating time and feedstock/inoculum ratio.
• The fuzzy model shows a better fitting to the experimental data compared to ANOVA. The proposed strategy, i.e., modelling and optimization, is an effective for increasing the biomethane yield at extended range conditions.

This article investigates the heat transfer through a novel type of heat exchanger in an industry that is extremely energy intensive. The investigations were carried out on a state-of-the-art experimental rig, and coupled with an original conjugate heat transfer numerical model. Furthermore, the numerical model was extended to a full-size SCHE, in the first study of its kind.

This study demonstrates that Thermoanaerobacterium thermosaccharolyticum W16 could perform high glucose and xylose fermentation for hydrogen production. Further investigation confirmed that strain W16 could consume glucose and xylose simultaneously with the absence of carbon catabolite repression, however, the glucose or xylose consumption rate would be slowed down with the addition of counterpart. Transcriptomic sequencing analysis suggested the activity of different sugar transporters was the main reason for the similar yet interactive characteristic of glucose and xylose catabolism by strain W16.

This article presents innovative eco-green portable wireless power charger system for portable electronic devices which offers more environment-friendly, enhanced consumer convenience and experience. It applied a wireless power transmission system using magnetic induction technique and a four-cell proton exchange membrane fuel cell planar module with free air-breathing cathode as a clean power source. With low-voltage and high-current fuel cell features, the apparatus provides power around 1.6 W to the device battery under recharging.

A machine learning-based energy consumption forecasting model has been proposed to predict the energy usage of 30 mixed-used buildings. Differences in the energy usage of the mixed-used buildings were captured in the developed forecasting model. The results further revealed a 46% decrease in the mean bias error and a 10% decrease in the coefficient of variation root mean square error for the mixed-used buildings.

A synthetic methodology for an advanced design of battery pack is proposed. Comprehensive recycling framework of battery and battery pack is discussed. Cumulative advantages of the methodology with six future critical directions are discussed.

1. An assembling device capable of applying uniform clamping force is built to facilitate fuel cell assembling and maintain the flow field uniformity.
2. With the optimum clamping force of 200 kgf, the cell performance is enhanced by 50%, due to reduced mass transfer resistance and interface resistance provided by the resultant uniform compression pressure distribution.

Role of perovskites as a bi-functional catalyst for electrochemical water splitting for economical production of hydrogen is crucial to develop a cheap catalyst that can replace noble metals . Electrochemical performance and durability of perovskite catalysts is reviewed.

A simple organic template-free method is proposed for the synthesis of sheet-like mesoporous Ni-silicate. The Ni²⁺ ion content in the filtrated solution is less than 0.1 ppm. The Ni-silicate demonstrated a high catalytic capability (>99%) toward the ammonia decomposition at 400°C.