Shell and tube heat exchangers (STHEs) are familiar for large-scale industrial applications due to their improved heat transfer area, ease of adoption of high temperatures and pressures, and flexible flow setup. However, uneven heat flow, variations in specific surface area, and limitations in heat capacity all contribute to the reduced thermal performance of a heat exchanger. The research objectives are to enrich the overall heat transfer and exergy efficiency behaviour of a shell and tube heat exchanger (STHE) with modified tube geometry. The effectiveness of circular, square, and polygon tube surface configuration on heat transfer rate, energy release rate, variations in heat capacity, and exergy behaviour of STHE is evaluated under natural convection. During the evaluation, a paraffin-based phase change material (PCM) was used as an energy storage medium, filled in a tube, and water served as the heat transfer fluid (HTF). With the significance of evaluated results, the circular tube geometry is found higher heat transfer rate (122.3 W), a higher energy release rate (0.052 kWh), and better heat capacity of PCM. Similarly, the exergy efficiency of a circular pipe is found to be 23.4 %, and 39.5 % superior to that of a square tube. Furthermore, the COMSOL Multiphysics simulation software was used to analyze the temperature distribution between the tube configuration and the PCM. Hence, the heat storage efficiency was validated using the simulation results, and the standard deviations were calculated as approximately 1.15, 0.85, and 1.2 for the circular, square, and polygon-tube configurations, respectively. Research has shown that the circular tube with PCM exhibits superior heat transfer performance and high exergy efficiency compared to other tube configurations, making it a suitable choice for heat exchanger applications.

In the context of energy demand, green hydrogen energy is a significant trend, playing a crucial role in various applications due to its pollution-free nature, improved efficiency, and superior fuel economy compared to fossil fuels. Here, the study involves producing the hydrogen syngas from food/kitchen waste water via supercritical water gasification (SCWG) methods. The experimentation is conducted with different gasification pressures (10-25 MPa) at a constant gasification temperature (550 degrees C) and residence time (30 min) using both Ru-based catalysts (1 wt% Ru) and Ru/Al2O3-supported catalysts. The experimentation results show that the improved pressure of gasification leads to a progressive enhancement in hydrogen syngas yield, better carbon conversion efficiency, gasification efficiency, and reduced tar formation. Furthermore, the setup configured with Ru/Al2O3-supported catalysts achieves 27.1 % of hydrogen yield, increases carbon conversion efficiency (5.2 %), optimizes gasification efficiency (7.8 %), and reduces tar formation by 21.2 % compared to the supercritical water gasification setup without a catalyst. This combination of an operated supercritical gasification system with higher gasification pressure is a trade-off for hydrogen syngas production from food/kitchen waste water, resulting in reduced tar and improved hydrogen gas formation.

This research study evaluates the functional properties of an aluminium alloy (Al6061) composite incorporating 3 wt

This study investigates how different thicknesses of the electron transport layer (ETL) impact the performance of Formamidinium lead iodide (FAPbI3) solar cells with a silver back contact. The solar cell structure includes a 200 nm-thick fluorine-doped tin oxide (FTO) window layer, a Formamidinium lead iodide layer for light absorption, and a tin(IV) oxide (SnO2) layer serving as the ETL, with thicknesses of 5, 10, 15, and 20 nm. Using the spin-coating method with anti-solvent treatment, followed by annealing at 400 degrees C, solar cells were fabricated with and without the SnO2-perovskite absorber. Results show that the ETL thickness significantly affects key performance parameters, including charge transport, recombination, and overall efficiency. The perovskite solar cells featuring with 20 nm SnO2 layer have a crystallite size of 40.1 nm. It also shows the lowest transmittance at 45 % and the highest absorption coefficient at 7.5 x 104 per cm. This material also has the highest refractive index of 2.2, the best conductivity of 0.55 x 10-2 S/cm, and the lowest resistivity at 1.82 x 102 Omega cm. Moreover, the optical band gap decreases to 1.52 eV, resulting in a higher short-circuit current density (Jsc) of 23.5 mA/cm2 and an open-circuit voltage (Voc) of 1.2 V. An optimum performance of perovskite solar cells featuring 20 nm SnO2 is recommended for solar cell applications.

Present research, production of high-performance and sustainable poly (lactic acid) (PLA) composite that integrated with short kenaf fibers (3-4 mm) and 3

Polymer-based fiber-reinforced composites are widely used for lightweight automotive structural components due to their distinct functional properties compared to monolithic polymeric matrices. However, conventionally synthesized composites exhibit low fracture toughness and moderate thermal stability due to poor load transfer, limited energy dissipation at higher impact loads, and the susceptibility of natural fibers to degradation at elevated temperatures. The main objectives of the present research are to enrich the thermo-mechanical characteristics of polycarbonate (PC) based poly matrix composite embedded with short Kevlar fiber and 2-6 wt% of boron carbide nanoparticle (B4C) via the injection mould technique. During the production, the hybrid nanocomposite contained 10 wt% Kevlar fiber/4 wt% of B4C is facilitated a higher tensile stress of 108 MPa, improved fracture toughness of 4.2 MPa m0.5, high hardness of 94 HRR, reduced thermal expansion of 42 & times; 10-6 per degrees C, significant enhancement in thermal stability, and provide better heat deflection behaviour, which is superior to monolithic PC poly matrix without Kevlar fiber and B4C nanoparticles. An optimal combination of Kevlar fiber and B4C nanoparticles in the PC matrix is a trade-off for lightweight automotive cabinet and seat frame applications.

The PCDTBT ((Poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)) is a familiar conjugated polymer utilized for optoelectronic and solar cell applications due to its significant functional characteristics, including wide absorption, improved open-circuit voltage, and suitability for solution processing. However, it found reduced variation in electron mobility, which affected the short-circuit current density and, consequently, the power conversion efficiency properties. This research overcomes the consequence and enriches the overall optoelectronic behaviour of PCDTBT-based organic photovoltaic (OPV) with an adaptation of zinc oxide (ZnO) electron transport layer (ETL) as 0, 10, 20, 30, and 40 nm thicknesses via radio frequency (RF) magnetron spattering technique and influences of ZnO ETL layer thickness on optical, electron mobility, charge transport, X-ray diffraction and PL (Photoluminescence) efficiency of PCDTBT is investigated. The optimized OPV structure features 40 nm ZnO nanoparticles incorporated into the PCDTBT active layer. The optimized structure achieves an open-circuit voltage (VOC) of 0.91 V, a short-circuit current density (JSC) of 15.09 mA/cm2, and a power conversion efficiency (PCE) of 8.5

Present research aims to synthesis and increase the tribo-mechanical performance of magnesium (AZ91) alloy composites embedded with a fixed loading of 5 µm molybdenum disulfide (MoS2) and 3–9 wt.

Currently, increasing the efficiency of power generation cycles is not the only goal for engineers; the focus is also on how it is achieved, whether through conventional or non-conventional energy sources. In conventional systems, changing the working fluid in the bottoming cycle has attracted engineers’ interest to boost cycle efficiency. Among various working fluids, carbon dioxide and ammonia water mixtures show promising thermodynamic properties that enhance both first and second law efficiencies. This research explores the use of transcritical carbon dioxide as the working fluid in the bottoming cycle of a combined cycle power plant with reheat cycles. The results indicate that, under operating conditions such as a topping cycle pressure ratio of 20, an ambient temperature of 303 K, and a turbine inlet temperature of 2000 K, the system performs better, with first law and second law efficiencies reaching 44.8

Hydrogen energy is a familiar form of green energy, which is gaining significance in automotive applications due to its unique properties and eco-friendliness compared to fossil fuels. Hydrogen energy is extracted from waste biomass, including algae, textile, and sewage wastewater, through a gasification process, which is effective and suitable for large-scale applications. However, this technique is limited due to a lack of carbon capture, variation in syngas production, and a lack of hydrogen selectivity. This research aims to resolve disputes and enhance hydrogen syngas production, increase hydrogen selectivity, and mitigate carbon capture behaviour during the extraction of hydrogen from sewage wastewater through a catalytic gasification process. During the gasification process, the gasification temperature of the gasifier is varied from 600 to 900 degrees C, with a 30-min residence time, using a 5 % potassium hydroxide (KOH) catalyst to enhance hydrogen selectivity and carbon capture. The effect of gasification temperature on the molar fraction of hydrogen, hydrogen yield, lower heating value (LHV), gasification efficiency, and hydrogen selectivity in the gasification system is evaluated. Gasifier configured with 5 % KOH operated at 900 degrees C for 30 min was found to have an optimum hydrogen molar fraction (4.2 % CO, 16 % CO2, 51 % H2, and 17 % CH4), higher hydrogen yield of 21 mol/kg, reduced LHV of 9 MJ/Nm3, superior hydrogen selectivity of 21.2 %, and enhanced gasification efficiency of 64 %. Finally, the extracted hydrogen energy is utilized in automotive applications.

Liquid stir casting is a familiar and efficient method used for the production of magnesium matrix composites, which are suitable for making complex structural components with specific properties compared to monolithic alloys. However, magnesium matrix composites processed with conventional stir casting faced challenges in uneven particle dispersion, porosity, and oxide formation, leading to limitations in the functional properties of composites. Current research utilizes the ultrasonic-aided stir-casting route to synthesize magnesium (AZ31) alloy composites under an argon atmosphere, thereby minimizing oxide formation. Finally, the AZ31 alloy composite consists of 2 wt

The solar-based hybrid automotive vehicle represents a trend marked by technological excellence, offering an efficient, cost-effective, and eco-friendly solution. Besides, the enhancement of solar absorption due to poor weather is influenced by poor solar power with reduced photocurrent density. This research focuses on enhancing the solar power and photocurrent density of conventional solar cells featuring aluminium-doped zinc oxide thin films (AZO) using the Mist Chemical Vapor Deposition (MIST CVD) process with a zinc acetate precursor solution processed at temperatures ranging from 200 to 400°C. To investigate the effect of AZO on the functional behaviour of solar cells, microstructural studies utilizing scanning electron microscopy and X-ray diffraction reveal the concentration of AZO and the alignment of Al/ZnO peaks as even. As a result, this research demonstrates a 21% increase in solar power output compared to conventional Cadmium Telluride (CdTe) cells, with an improvement in photocurrent density of 1.24 mA/cm2. This advanced solar cell technology is recommended for use in electric vehicle (EV) applications.

Cadmium telluride (CdTe) has potential for solar cell applications and has unique properties such as a high absorption coefficient, economic, better power conversion efficiency, and better stability. However, variations in transmittance, lower p-type conductivity, and recombination loss due to interface defects. This research intends to overcome and enrich the opto-electrical properties of CdTe featuring a 40–70 nm (with 10 nm interval) Zinc selenide (ZnSe) buffer layer and a constant layer thickness of molybdenum (Mo) back contact through the thermal evaporation technique. The effect of ZnSe layer thickness on opto-electrical properties of CdTe cell layers is investigated, and at the optimal ZnSe thickness of 70 nm, XRD analysis reveals a significant improvement in crystallinity and grain growth, with a grain size of 48 nm. Additionally, electrical conductivity reaches 7.5 × 10–3 S/cm, and transmittance increases to 72

The worldwide shift toward low-carbon energy systems has heightened the academic interest in biohydrogen generated from renewable biomass, positioning it as a viable and sustainable fuel alternative. This review provides a critical analysis of biological pathways, namely dark fermentation (DF), photofermentation (PF), and microbial electrolysis (MEC), in conjunction with thermochemical methodologies, including pyrolysis, gasification, and supercritical water gasification (SCWG). Biological routes generally produce 1.8–2.5 mol of H 2 per mol of hexose-equivalent substrate, which necessitates reduced energy input and results in minimal carbon emissions. Conversely, thermochemical conversion can yield over 10 mol H 2 kg −1 of dry biomass at elevated temperatures (>600°C), albeit with issues surrounding catalyst degradation. Hybrid systems, particularly DF-PF and DF-MEC configurations, exhibit enhanced carbon conversion efficiencies, achieving up to 5.2 mol H 2 mol −1 of substrate under optimized laboratory-scale conditions that align with Technology Readiness Levels (TRL 3–4). Novel advancements, including microwave-assisted pyrolysis (MAP), magnetic nanoparticles (MNPs) catalysis, and artificial intelligence (AI)-driven optimization frameworks, indicate significant potential for improving yield, flexibility, and real-time process regulation. Comprehensive techno-economic analyses (TEA) and life cycle assessment (LCA) evaluations reveal pathway-specific compromises, emphasizing the necessity for standardized sustainability metrics, adherence to environmental health and safety (EHS) regulations for nanomaterials, and supportive policy frameworks to promote the advancement of biohydrogen toward commercial feasibility and climate-resilient implementation.

In recent trends, renewable energy has gained significance in worldwide applications due to avail from nature, low cost, and pollution-free. Based on the world population, a large volume of municipal and sewage water waste affects the environmental water sources, resulting in pollution. To save the earth and maintain a green environment, the present investigation aims to produce bio-hydrogen from municipal and sewage waste through a gasification process with a pyrolysis reactor. The temperature and time of the gasification process were varied by 600-900°C and 60 min. The impact of gasification temperature (600-900°C) and 60 min on molar fraction, gas yield, and gasification efficiency behaviour has to be investigated, and higher temperature (900°) with 60 min gasification process showed the superior molar fraction with 18.4 mol/kg hydrogen yield and improved gasification efficiency of 72%. The gained bio-hydrogen suggested energy storage applications.

With unique properties such as enhanced photoluminescence (PL) efficiency, improved thermal stability, and favourable optical properties, polyfluorenes (PFs) are well-suited for organic light-emitting diode (OLED) applications. However, the conventional PF layers are found to have drawbacks, including variation in charge transport, which minimizes the overall PL efficiency due to uneven coating and photo-oxidation. Current research aims to overcome the above difficulties and to synthesize PF reinforced with alumina (Al2O3) nanoparticles (3 wt%) along with encapsulation coating via Atomic Layer Deposition (ALD) and investigates the influence of varying encapsulation coating thicknesses (0, 10, 30, and 50 nm) in the enhancement of optoelectronic performances and operational stability. The fabricated devices were characterized using electroluminescence (EL) spectra, external quantum efficiency (EQE), current-voltage (I-V) plots, and encapsulation effectiveness tests. The investigational results indicate that an encapsulation thickness of 30 nm yields the maximum EL intensity, with a peak wavelength of 470 nm and an external quantum efficiency (EQE) of 8.1 %. This configuration exhibited a low turn-on voltage of 3 V. The I-V plot demonstrated a maximum current density of 8.2 mA/cm2. The Hall mobility was increased to 1.0 x 10-4 cm2/V.s with the observed carrier concentration of 2.6 x 1016 cm-3. The alumina encapsulation significantly improved the durability and stability, with a device lifetime of 312 hours, and reduced the oxygen permeation rate to 5 cm3/m2/day/atm. The findings highlight the crucial role of optimizing alumina encapsulation thickness in enhancing the functional performance of PF-based OLED devices.

Poly (3-hexylthiophene) (P3HT)-based conductive polymers exhibit superior optoelectronic properties and are utilized in sensors, organic light-emitting diodes, and organic photovoltaic applications. This research aims to synthesize a high-performance P3HT conductive polymer that incorporates titanium dioxide (TiO₂-30 nm) in various ratios of P3HT to TiO₂ nanoparticles, using solution processing enhanced by the spin coating method and improving its structural quality through thermal annealing. The study investigates how different P3HT: TiO₂ ratios affect the optoelectrical behaviours of the P3HT hybrid layer, including optical absorption, photoluminescence (PL), ultraviolet (UV) sensitivity, electron transfer rate, energy level, and electrical conductivity, and compares these results with previous findings. The results revealed that a 1:1 composition demonstrated the most balanced and enhanced performances. The integration of 30 nm TiO2 nanocomposites improved the electron transfer rate, photoluminescence (PL) quenching, electrical conductivity, and optical absorption. The 1:1 P3HT: TiO₂ showed substantial improvement in UV sensitivity resulting from the band alignment between P3HT and TiO₂. This optimized composition achieved an optical absorption intensity of 1.12 a.u. and a PL intensity of 610 a.u. It exhibited the highest UV sensitivity of 7.9 due to the optimal interfacial interaction. It demonstrated a maximum electron transfer rate of 1.0 a.u. with minimal recombination losses. The optical bandgap was observed as 2.30 eV and electrical conductivity as 1.8 × 10⁻⁴ S/cm. Thus, the current paper demonstrated an effective strategy to overcome the lack of UV detection of P3HT polymers, making them suitable for UV photodetector applications.