Solar distillation is an environmentally friendly method of producing freshwater, yet its use at large is constrained by low productivity (usually 3 L m−2 day−1) and reliance on the daytime solar radiation. Thermal energy storage (TES) materials, especially phase change materials (PCMs) and nanoparticle-enhanced PCMs (NePCMs), are promising solutions to extend operation into non-sunlight hours and improve thermal efficiency. The reviewed studies show that the use of TES can enhance productivity by 20–75

The efficiency and sustainability of solar panels throughout the day remain significant challenges, primarily due to the temperature rise in solar cell materials during peak sunlight hours, which reduces their efficiency. This study aims to enhance the efficiency of solar panels using an air-cooling mechanism. Based on prior insights, an indoor experimental setup was developed, featuring a cooling system with 196 circular pin fins, each with a diameter of 3 mm and a length of 16 mm, mounted on the rear surface of the solar panel. An aluminum heat sink of 3 mm thickness was integrated to support the fins, while a variable-speed fan supplied airflow across the fins. The solar flux and airflow rate were identified as critical parameters influencing solar panel efficiency. These parameters were optimized using Response Surface Methodology, with ranges of 400-800 W/m2 for solar flux and 0.01-0.02 m3/s for airflow rate. Optimization was performed using MINITAB 17 and Design Expert 18 software. The optimized input conditions, solar flux of 403.33 W/m2 and airflow rate of 0.0221 m3/s, yielded the following outcomes: exergy efficiency of 15.79%, power output of 4.12 Wp, module temperature of 22.43 degrees C, and solar panel efficiency of 14.48%, with a composite desirability score of 0.5737. This work is novel and new in its simple and light weight arrangement as compared to heavy vibrating pumps required in liquid and nano-fluid cooling. Additionally, the optimization approach and economic analysis of the solar panel cooling system are relatively new and have received little attention in previous literature. Perturbation plots revealed that solar flux had a more pronounced effect on panel performance compared to airflow rate. This study highlights the potential of air-cooling systems to mitigate midday efficiency losses and improve the operational sustainability of solar panels. The findings contribute to advancing cooling technologies for solar energy systems, promoting greater energy efficiency and reliability.

In today's scenario, biodiesel is one of the best alternatives to diesel for application as an eco-friendly product. In this work, jojoba oil is transesterified using solar energy for heating purposes. A solar parabolic trough collector having 6.4 m(2) and 89% reflectivity is used to concentrate solar rays on a sealed container containing jojoba oil and catalyst-alcohol mixture, placed at the focus of the dish. The performance parameters like molar ratio (MR), reaction time (RT), and catalyst concentration (CC) are optimized. The result showed the highest yield of 89.67% at the optimum condition of molar ratio 9:1, reaction time 120 min, and catalyst concentration 0.8 wt.%. The highest contribution of 55.13% is measured for the molar ratio, followed by reaction time and catalyst concentration. Later, the interaction between MR, RT, and CC is established by response surface/contour plots; and their effects on biodiesel yield are discussed. Subsequently, the various physicochemical properties of raw jojoba oil and jojoba oil methyl ester are also measured and discussed as per ASTM standards. The unsaturated acid content in the biodiesel is also measured by gas chromatography. Hence, the blends of linseed oil with diesel fuel can be used in the IC engines with little or no modifications in engine parameters. Therefore, the use of solar energy could effectively reduce the use of electricity to cut down the processing cost in biodiesel production. Also, the methods should be established for methanol recovery from glycerine.

The present study explored the benefits of using the trapezoidal plate as a heat exchanger over the plain plate in a PVT unit (conventional unit). The study compares the performance based on annual energy and exergy generation, key energy matrices, CO2 mitigation, and corresponding carbon credits. Initially, the airflow rate was optimized from the range of values 0.0039-0.0117 kg/s, identifying 0.0094 kg/s as optimal for the annual performance assessment. Experiments were carried out on the rooftop of the Department of Mechanical Engineering, NIT Silchar, India, from December 2022 to November 2023. Results indicate that the trapezoidal plate-based unit maintains a 2.8 degrees C lower PV module temperature and a 1.9 degrees C higher outlet temperature compared to the conventional unit. The exergy destruction rate of the trapezoidal plate unit is 1.89 % and 2.73 % lower than the conventional unit on a typical winter and summer day. Additionally, it generated 8.7 %, 8.4 %, and 1.62 % higher annual overall energy, overall exergy, and net electrical energy than the conventional unit. The energy payback time achieved by the trapezoidal plate unit is 9.5 % (overall energy) and 5.4 % (overall exergy) less than the conventional unit. Additionally, the trapezoidal plate unit mitigates 8.6 % and 8.8 % more CO2 mitigation annually on an overall energy and exergy basis, respectively.

This review study thoroughly examines the performance variables influencing solar stills, such as reflectors, varying water depth, design, geometry, ambient temperature, and solar intensity. The review devotes a large amount of attention to sophisticated enhancement methods, including the utilization of nanoparticles, PCM (phase change materials), and PCM incorporated in nanoparticles. The potential for efficiency gains through the use of hybrid nanofluids and nano-coating materials is also investigated. Through a comparative examination, the paper outlines the advantages and difficulties of each method. Key investigations on water depth, reflector integration, and advanced materials are also summarized using tabular data. Results show that using these cutting-edge methods significantly increases solar still production, opening up exciting new research and development opportunities for renewable energy systems.

Abstract In this work, thermo-hydrodynamic simulation was carried out for bulb-shaped ribs roughened absorbing surface of solar air heater at 1kW/m2 for and various Reynolds numbers. Primarily, sensitivity analysis of turbulent models was carried for flow over the surface, and it observed that RNG k-\(\epsilon\) model results is more closed with respect to Dittus-Boelter equation. After selection of appropriate turbulence model, simulations were carried out on a bulb-shape rib and other shapes of roughened ribs surface. This study reveals that absorber bulb shaped ribs roughened surface has at least two times more performance improvement factor (Nu/f) as compared to the other ribbed shape roughened surface. Eventually, the Nusselt number and Coefficient friction for bulb shaped ribs roughened surface were correlated in terms of Reynolds number (Re) and relative roughness (β). These correlations are substantial for designing solar air heating systems for bulb-shaped ribs roughened as absorbing surface.

The objectives of the present work are to examine the combined effect of engine operating and injection parameters and to optimise these parameters for better fuel economy, performance, and reduced emissions. The fuels used were diesel and biodiesel blends of Jatropha and Karanja biodiesel. The results indicate that diesel gives higher thermal efficiency at low loads, however, the 20% jatropha blend was slightly more efficient, at high loads. It was observed that the BSFC increases when the EGR is varied from 0% to 20%. Even though the smoke opacity increases with increased EGR, advanced injection at 28o BTDC decreases smoke. Increased EGR also reduced NOx emissions by up to 11%. Blending also has a significant impact on the output parameters. Taguchi analysis was applied to optimise the performance and emission characteristics of the diesel engine and set of input values were obtained for the optimum performance under different conditions.

Green cement concrete is an environmentally friendly variant of concrete manufactured using industrial waste. This sort of concrete has the potential to have a lower environmental impact than traditional concrete production while also providing a more durable and cost-effective alternative. This article offers experimental work on using industrial waste in green cement concrete, which is advantageous because it minimizes the amount of garbage transported to landfills along with dry geopolymer. According to this study's findings, industrial waste can lower production costs because it is typically less expensive than traditional resources and the amount of energy required to manufacture concrete because it is often lighter than conventional materials. Dry geopolymer is a substance formed from silica, alumina, and calcium. Because of its excellent resistance to water and other factors, this material is ideal for use in green cement concrete. Furthermore, dry geopolymer green concrete is lighter than regular concrete, lowering the energy required to manufacture the concrete. Green cement concrete made from industrial waste and dry geopolymer is an excellent way to reduce the environmental impact of traditional concrete production. It is also more durable and less expensive than typical concrete, making it a perfect solution for various construction applications.

In this research paper, a well-performing solar pump at the minimum cost of project life is designed and installed. Initially, the capacity of submersible pumps and discharge have been determined based on the water requirement of the crop and the size of the field. The total number of solar panels, inverter size, and motor pump system have been designed based on the law of conservation of energy. The two optimization techniques genetic algorithm (GA) and response surface methodology (RSM) have been used for analyzing the pump performance parameters and total cost. The GA tool has been used to determine the optimum tilt angle on which responses namely solar flux, solar panel efficiency, exergy, and pump efficiency should be maximum. Moreover, the performance of the solar pump at the optimum tilt angle has been compared with the 28(degrees) fixed tilt angle (latitute of location). For the experimental study solar pump experimental setup of 5 hp power has been installed in Faculty of Engineering and Technology, MJP Rohilkhand University at 28.36(degrees)N, 79.43(degrees)E. The total cost of the solar pump has been optimized with the help of RSM based on the discharge and head of the solar pump. The new optimization approach reduced the levelized cost of electricity (LCOE) from 0.041 to 0.035 $/kWh and the payback period is reduced from 4 to 3 years. The annual increment in average solar flux and overall efficiency has been recorded to be from 606 to 697 W/m(2) and 11% to 14% respectively.

Aldose Reductase 2 (ALR2), a key enzyme of the polyol pathway, plays a crucial role in the pathogenesis of diabetic complications. Quinoxaline scaffold-based compounds have been identified as potential ALR2 inhibitors for the management of diabetic complications. In the present work, molecular dynamic simulation studies in conjugation with pharmacophore mapping and atom-based 3D-QSAR were performed on a dataset of 99 molecules in comparison with Epalrestat (reference) to mark the desirable structural features of quinoxaline analogs to generate a probable template for designing novel and effective ALR2 inhibitors. The most potent compound 81 was subjected to MD simulation studies and found to be stable, with better interactions with the binding pocket as compared to Epalrestat. The MM-GBSA and MM-PBSA calculations showed that compound 81 possessed binding free energies of -35.96 and -4.92 kcal/mol, respectively. Atom-based 3D-QSAR yielded various pharmacophoric features with excellent statistical measures, such as correlation coefficient (R2 value), F-value (Fischer ratio), Q2 value (cross-validated correlation coefficient), and Pearson's R-value for training and test sets. Furthermore, the pharmacophore mapping provided a five-point hypothesis (AADRR) and docking analysis revealed the active ligand-binding orientations on the active site's amino acid residues TYR 48, HIE 110, TRP 111, and TRP 219. The results of this study will help in designing potent inhibitors of ALR2 for the management of diabetic complications.Communicated by Ramaswamy H. Sarma

In this research paper,a solar air heater with triangular fins has been experimentally analysed and optimized.Initially,an experimental set-up of a solar air heater having triangular fins has been developed at the location of 28.10°N,78.23°E.The heat transfer rate through fins and fins efficiency has been determined by the Finite Difference Method model equations.The experimental data and modeled data of response parameters have been optimized in MINITAB-17 software by the Response Surface Methodology tool.For creating the response surface design,three input parameters have been selected namely solar intensity,Reynolds number,and fin base-to-height ratio.The range of solar intensity,Reynolds number,and fin base-to-height ratio is 600 to 1000 W/m2,4000 to 6000,and 0.4 to 0.8 respectively.The response surface design has been analyzed by calculating the outlet temperature,friction factor,Nusselt number,fin efficiency,thermal performance factor,and exergy efficiency.The optimum settings of input parameters:solar intensity is 1000 W/m2;Reynolds number is 4969.7,and the fin base to height ratio is 0.6060,on which these response:namely outlet temperature of 92.531℃,friction factor of 0.2350,Nusselt number of 127.761,thermal efficiency of 50.836％,thermal performance factor of 1.4947,and exergy efficiency of8.762％.

In this research paper, three different arrangements of Solar Air Heaters (SAH) have been modeled and experimentally analyzed. The first solar heater is the Simple Solar Air Heater with tin cans, second has added reflecting mirrors with tin cans and third has a triangular fins arrangement on a copper plate. The outlet temperature of the air, solar heater efficiency, pressure drop, exergy, and exergy destruction have been determined for three arrangements of solar air heaters and compared with each other. The best performer SAH among the three was finally validated with the previous study on evacuated tube pipe solar air heater. After experimental and modeling results, it is concluded that the performance of evacuated tube pipe solar heater is better than tin cans reflecting mirror solar air heater in morning and evening and at noon the performance of reflecting mirror solar air heater is better since the addition of reflecting mirrors increase the heat supplied on the tin can tube in the afternoon time.

The internal combustion (IC) engine has proved to be the pivotal technology to meet the transportation needs of ever-increasing populations. IC engine technology and its future are mainly dependent on fuel sources for which the demand is continuously rising worldwide. One such fuel that has the potential to replace diesel (fossil) fuel for IC engines is biodiesel. Its inherent characteristics such as renewability, biodegradability, enhanced lubricity, cetane number, abundance in feedstock, availability at local level, and better emission profile provide easy acceptability of biodiesel. However, their suitability is hindered by a few shortcomings, including inferior oxidative stability, poor cold flow properties, high viscosity, lower volatility, unsaturated fatty acid esters, water absorbency, and lower heat of combustion. These alternative fuels are less efficient if they are utilized directly as fuel in diesel engines. Therefore their characteristics must be appropriately modified by varying the properties that are pertinent to maximum engine power and thermal efficiencies with reduced fuel consumption and reduced engine tail pipe emissions. This chapter discusses the efforts of different researchers and their suggested methodologies in modifying biodiesel fuel characteristics. This work will also pave the way toward wider acceptability of biodiesel fuel.

India is a country that has an abundant amount of solar energy. Air Heating is a famous application of solar energy. The heated air can be used in industry in number of application like crop drying, wood seasoning and in refinery. The Solar Air Heater is the device which is used for heating the air with the help of solar energy. In this study, the two designs of solar air heatesr analyzed and compared. The first design consists of triangular fins produced over absorber plate and second one has the tin can pipes fixed over the absorber plate. The comparison of both solar heaters was made based on Heat transfer rate, efficiency, Nusselt number, friction factor and pressure drop. The average enhancement in temperature difference is found 32.77 °C and 30.18 °C in October and 22.64 °C and 20.42 °C in December in Can Solar Air Heater (CSAH) and Ribs Solar Air Heater (RSAH) respectively. In CSAH, the average heat transfer rate is improved by 7.65 % and 10.17% in October and December respectively as compared to RSAH. The Performance of CSAH is more than 7.17% and 12.41% as compared to RSAH in months of October and December. The finding showed that the CSAH works better than the RSAH in forced convection. In both types of Solar heaters it is found that as enhancement in mass flow rate increase the pressure drop and Nusselt number but the friction factor decreases. Both designs of SAH namely CSAH and RSAH are new in the area of solar air heater and proved to be very effective in transfer the heat and creating the turbulence in the air flow path.

In this study, roughness in the form of multi-V ribs having trapezoidal slots were crafted over the surface of absorber plate for enhancing the heat transfer rate in a solar air heater. An ex-perimental setup was designed and fabricated for demonstrating the performance of this plate with respect to smooth absorber plate. The setup has a double glazed-double pass air flow arrangement. The experiments were conducted under Indian climatic conditions (Latitude = 28.53˚N and Longitude = 77.39˚E) in September and October 2021 at various rates of air flow through the duct. The results of the roughened absorber plate were compared with the smooth absorber plate. It shows that the multi-V ribs with trapezoidal slots have higher efficacy as compared to smooth absorber plate in the order of 10.42% at an air flow rate of 0.078 kg/s. In addition, the present data of proposed roughness were also compared with data of various roughness available in the literature. It was found that the maximum thermo-hydraulic perfor-mance parameter of the proposed roughness texture is higher than other shapes of roughness texture. It was also found that the combination of double-glass cover and double-pass arrange-ment with the proposed roughness geometry increases the efficiency of the solar air heater at least by one order of the present solar air heating system.

Vapor compression refrigeration system (VCRS) based conventional cooling systems run on the high amount of electricity and refrigerants responsible for greenhouse emissions. To save the environment and high-grade energy, traditional cooling systems should be replaced with some environment-friendly alternative. This paper proposed alternative eco-friendly air-conditioning systems based on an amalgam of two different technologies, i.e., desiccant dehumidification and thermoelectric (TE) cooling. The proposed air-conditioning system has the following subprocess: dehumidification of moist air by the solid desiccant wheel, cooling of processed air by TE modules, and regeneration of desiccant wheel by an electric heater and waste heat from TE modules. The air conditioning system has been experimentally studied for cooling performance, cooling effect, and energy input. The maximum coefficient of performance of 0.865 can be achieved with the proposed system, and it can be used for cooling effects up to 1442.24 W to maintain the human comfort condition in the chamber i.e. approximately 22 ℃ and RH 50% defined by ASHRAE.

In this research paper, a SAH with triangular fins has been experimentally and numerically analyzed and validated. For numerical investigation Compressed Fluid Dynamics (CFD) software has been used to determine the velocity, pressure, and temperature field. The heat transfer rate through fins and fins efficiency has been determined by the FDM model equation. The heat transfer coefficient and friction factor are two important parameters that are used for determining the heat transfer rate and pressure drop over the surface of SAH. The HTC and FF have been optimized by the Response Surface Methodology (RSM). The optimum values of response parameters heat transfer rate, Nusselt Number, heat transfer coefficient, and friction factor are obtained to be 1224 W, 1224, 18, and 0.015 at Reynolds Number 170710, solar flux 1000 W/m2and P/L 3.52. For CFD analyses the RNG, K-Ô‘ model has been used by Roseland boundary conditions.

Electric Vehicles (EVs) will be a major mode of road transportation in short period of time. Batteries are the major source of energy storage for propulsion of EVs in which Li-ion batteries are currently the most suitable option. A suitable temperature range of 15-400C must be maintained for optimal performance and safety of Li-ion batteries, which can be achieve through battery thermal management system. In this study, a PCM based thermal management system has been drafted by considering the heat dissipation rate for 1C, 2C and 3C discharge rate of Li-ion batteries and simulated in ANSYS FLUENT 19.2 software. Suitable alternatives are suggested for the efficient performance of battery thermal management and the effects are also discussed. The result shows that PCM based system was able to hold the battery temperature below 400C with 1C, 2C and 3C discharge rate for time interval of more than 3600 seconds. PCM based system with thickness 10mm shows better result when compared with 6mm and 8mm while the couple PCM based system performs better than PCM with capsule system.

In this paper, a 335 W solar panel with a centrifugal pump combined system was simulated in MATLAB Simulink 2018 with fuzzy logic-based MPPT, and the voltage, current, power, and discharge four output responses were determined at different values of solar flux, module temperature, and atmospheric temperature.Further, the output responses voltage, current, power output, and discharge data have been optimized in Response Surface Methodology (RSM).The output data of RSM and MATLAB Simulink is used to determine the solar pump's theoretical performance and overall efficiency.Finally, the RSM-optimized results of solar pumps are validated with the experimental results of the solar pump.The experimental setup consists of 15 panels of 335 W power and a 5 hp submersible pump operated by an AC motor.The experimental data were collected from 15/01/2020 to 15/12/2020.The optimization of the solar pump by the three most important variables solar flux, module temperature, and the atmosphere temperature is very new and unique since the selected input variables maximize the overall performance of the solar pump.

Cooling system based on vapour compression refrigeration system runs on high amount of electricity and refrigerants that are responsible for green house emission. In order to protect environment and to save valuable high grade energy there is a need to replace VCRS based cooling systems with some alternate methods having less energy demands. Desiccant based system which is driven by renewable energy is one of the better substitute to replace VCRS. In the present work, a new approach for the air-condoning is adopted using the amalgam of desiccant dehumidification and thermoelectric cooler for cooling and drying of the process-air up to human comfort condition approximately 22 °C and RH 50% defied by The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) before entering to the cooling chamber. Maximum COP of the solar power driven system is reported to be 0.861 and it as an eco-friendly alternative of VCRS based systems.