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Solar energy systems operate directly connected to the sun. Solar chimney power plants are privileged systems that can provide power output even in cloudy weather and during hours when there is no sun. The design and sizing of this system, which researchers focused on after its first application in the 1980s, is very effective on its performance. In this study, the collector slope and chimney slope that give maximum power output for the Manzanares pilot plant are investigated with a 3D CFD model. Simulations made using the RNG k-e turbulence model and the DO (discrete ordinates) solar ray tracing algorithm provide results that are in high compatibility with experimental data and literature. It is understood that the system provides maximum power at 0.6° collector slope and 1.5° chimney divergence angle. It is seen that the system, which gives a power output of approximately 46 kW in the reference case, exceeds the power output by 4.5 times and reaches 216.853 kW in the design that includes the collector and chimney slope. The effects of the main elements of the system on the performance are also included by changing the collector radius and chimney height while preserving these inclination angles. More than the power output in the reference case, 49.233 kW, can be achieved with the inclined design, with a collector radius of 73.2 m and a chimney height of 155.68 m. Although the effect of increasing the chimney height on power output continues after 1.2 floors, its effect decreases. In the study, it is seen that increasing the chimney height and changing the collector radius provide a greater increase in power output. Furthermore, the scope extends to the incorporation of an Artificial Neural Network (ANN) model, presenting a novel approach to predicting SCPP system performance. The findings ascertain the utilisation of 9 neurons in the hidden layer of the ANN, demonstrating a precise alignment with the study data.

Alternative fuels are renewable sustainable and address socio-economic and environmental concerns. In this circumstance, this work is conducted in two stages. The first stage of the work involves, the preparation of nanoparticle (NP) blended fuels by adding 20, 40 and 60 ppm of multi-walled carbon nanotube (MWCNT) particles in dairy scum oil methyl ester (DiSOME) biodiesel using a mechanical homogenizer and ultrasonicator. Then, the steadiness characteristics of nanoparticle–mixed biodiesel fuels were studied under static state. In the next stage of the work, the effect of nanofluids on the attributes of combustion and emissions of aengine with 1-cylinder 4-stroke DI-direct injection),CI-compression ignition)which is run on DF-dual-fuel mode using DiSOME and PG-producer gas, has been examined. Investigation results indicated that at 80% load, DiSOME-PG combustion with 40 ppm of MWCNT nanoparticles provided 5.7% increased BTE, 23.5% decreased smoke opacity, 21.8% decreased HC, 22.4% decreased CO and 20.1% amplified NOx emissions related to the same fuel mixer but not with NPs. Adding NPs increased HRR - heat release rate and CP - cylinder pressure.

This experimental study is focused on heat transfer performance and pressure drop characteristics of ZnO/DIW-based nanofluids (NFs) in horizontal mini tubes of different (1.0–2.0 mm) diameters. Different mass concentrations (0.012–0.048 wt %) of nanoparticles (NPs) were tested with varying fluid flow rates (12–24 ml/min) of NFs. The thermal conductivity (TC) and viscosity (VC) of stable NFs were tested at 20–60 ᵒC, at a fixed temperature (40 °C), and concentration of NPs (0.048 wt%) the maximum rise was 18.27% and 20.31%, respectively. The local and average heat transfer coefficients (HTCs) and the pressure gradient were noticed to be directly proportional to volume flow rate of NFs and the mass concentration of NPs. However, an inverse trend was noticed with the test section's diameter. At 0.048 wt % of NPs and 24.0 ml/min flow rate of NFs, the maximum rise in local and average HTCs and pressure gradient was 17.11–11.61% and 13.05–9.79%, and 29.19–12.25%, respectively, in a tube's diameter of 1.0–2.0 mm. The friction factor increased with NP's loading while the same reduced with the fluid flow rate. The corresponding maximum change in the friction factor was 28.85–12.72% for the tubes with 1.0–2.0 mm diameters, respectively, at a 12.0 ml/min flow rate of NFs. The comparison of experimental findings for the HTCs, pressure gradients and friction factors with the standard Shah and Darcy's correlations showed that the observations are in good agreement with the predicted ones.

Due to the rapid economic growth and rising Oman population, Oman's annual energy demand has increased by approximately 9%. This percentage signifies that there is a considerable expansion of industries and other manufacturing sectors as the population increases. A study of the energy audit of International Maritime College Oman (IMCO) was conducted to determine the opportunities to save energy efficiency costs, which will be reflected positively in reducing the operational costs of the buildings. In this study, the annual energy consumption of IMCO buildings was simulated using DesignBuilder software. The validation of the simulation results was performed using monthly electricity consumption billing records, with an average of 7.4% during all months. Two strategies were proposed to manage energy consumption: replacing the traditional fluorescent lamp with a LED lamp light control and installing window solar films that are able to control solar heat. The simulation results of the two strategies showed 16% and 7.6% reductions, respectively, in energy consumption. A cost analysis of the findings was performed and showed a payback period of less than 2.5 years for both proposals.

In the current study, the ratio of a precise heat transfer growth to the different wt.% of the Zinc oxide-DW (ZnO-DW) based nanofluids are considered in a closed single-tube circular heat exchanger experimentally and by using ANSYS modeling. Four varying concentrations, 0.1%, 0.075%, 0.05%, and 0.025% wt. of the ZnO-DW nanofluids were considered and their thermal and hydrodynamic characteristics were determined experimentally and numerically. The experiments were conducted with base fluid (distilled water) as a working fluid for the validation of the 2-D numerical model. Using ANSYS-Fluent, a 2-dimensional domain was constructed and k-ϵ turbulent model was utilized to evaluate the continuity, energy, and momentum equations. All the nanofluids were experimentally and numerically examined with Reynolds (Re) numbers ranging from 5849 to 24544 and then validated using empirical correlations. Reynolds (Re) number, heat transfer coefficient, and Nusselt number were calculated and analyzed. The highest pressure drop was noticed for 0.1 wt% which is about 11184.9 m.Pas, while the highest friction (f) was 0.072983. Similarly, the maximum average heat transfer coefficient (h) and average Nusslet numbers (Nu) were been calculated both numerically and experimentally. At the highest 0.1 wt%. concentration of the ZnO-DW based nanofluids the supreme heat transfer was recorded about 13799.50 W/m2.K (71%) and the average Nusselt numbers (Nu) were noticed 176.47 (67.3%). Both experimental and ANSYS modeling results reflected that the 0.1% ZnO-DW based nanofluids contributed the highest heat transfer coefficient with an overall average deviation up to ±9.2%. Both experimental and numerical results showed promising and similar outcomes.

Perovskite solar cells (PSCs) are rapidly emerging as efficient solar cells due to the efficient photovoltaic and physiochemical properties. Ideally, the absorber layer in PSCs is sandwiched between highly conductive electron transport layer (ETL) and highly stable hole transport layer (HTL). The interfaces between these layers highly affect the performance of PSCs. In this study Magnesium (Mg) doped TiO2 based ETL is systematically investigated to enhance the optical and morphological properties of the layer and the interface. It was observed that with Mg doping in mesoporous TiO2, morphology of TiO2 based ETL film was significantly improved thereby providing an interface for the growth of absorber layer. Optoelectronic studies suggested that band gap was effectively reduced with the addition of Mg and absorption range was also enhanced. Electrical analysis yielded, Mg doped TiO2 based ETL showed enhanced conduction and better sheet carrier mobility as compared to undoped films. Thermal studies indicate fabrication of a thermally stable ETL material for PSCs. Moreover, Current density-Voltage (J-V) measurements indicated more than two-fold increase in photovoltaic efficiency of 3 wt% Mg.

In the current study, an effort is carried out to study the influence of pentanol as low reactive fuel (LRF) along with diesel and Thevetia peruviana methyl ester (TPME) as high reactive fuels (HRF) in reactivity controlled compression ignition (RCCI) engine. The experiments are conducted on dual fuel engine at 50% load for RCCI mode of operation by varying pentanol percentage in injected fuels. The results revealed that RCCI mode of operation at 10% of pentanol in injected fuels exhibited higher brake thermal efficiency (BTE) of 22.15% for diesel and pentanol fuel combination, which is about 9.1% and 27.3% higher than other B20 and pentanol, B100 and pentanol fuel combinations respectively. As the percentage of pentanol increased in injected fuels, hydrocarbon (HC) and carbon monoxide (CO) emissions are increased while nitrogen oxide (NOx) and smoke emissions are decreased. Among various fuel combinations tested diesel and pentanol fuel combination gives lower HC, CO and smoke emissions and higher NOx emissions. At 10% pentanol in injected fuels, the highest heat release rate (HRR) and in-cylinder pressure are found for diesel and pentanol fuel combinations compared with other fuels.

Environmental concerns have urged a search for eco-friendly refrigerants in the refrigeration industry to overcome ozone depletion and global warming problems. Therefore, current research emphasizes frictional pressure drop during flow boiling of environment-friendly refrigerants (GWP