The failure of a porcelain insulator on a transmission line is a crucial cause of power supply interruptions, leading to poor reliability and revenue loss. The insulator’s performance is adversely affected by environmental contaminants, and wettability intensifies this adverse effect by developing a conductive path along the insulator’s surface, leading to premature flashover and insulator failure. This work aims to analyze the response of the electric field distribution and current density using the finite element method (FEM) under different wettability conditions. Discrete water droplets were placed along the surface, and the contact angle was varied to represent different levels of surface hydrophobicity. Abrupt rises and spikes were observed on the plots for the electric field and current density distribution, indicating distortion; however, the distortion kept on decreasing with the increase in the contact angle. Overall, the average stress followed a declining pattern, where the values of the electric field were reduced from 2.588 to 2.412 kV/cm, and current the density was reduced from 0.187 to 0.068 nA/cm2 for an increase in the contact angle from 60° to 140°. Simulation results advocate for hydrophobic insulator surfaces. Therefore, a proper coating is necessary to enrich hydrophobicity and mitigate the adversity of wettability. Polyurethane, due to its excellent hydrophobic and insulating properties, offers a potential coating. Flashover voltage tests have been performed for the coated insulator under dry and wet conditions, where the flashover voltage improved from 79.14 kV to 82.04 kV and 48.4 kV to 53.8 kV, respectively, which supports the simulations’ outcomes.

Pakistan is facing an escalating energy crisis that demands immediate and sustainable solutions. To address this challenge, this study evaluates the feasibility of solar energy production through a techno-economic analysis of a 1.5 MWp photovoltaic system. The analysis combines PVsyst simulations with real-time operational data collected between June 2023 and January 2024, enabling a direct comparison between predicted and actual system performance. The study examines energy yield, performance ratio, and financial metrics to assess economic viability. Results reveal that the average performance ratio was 82.7% in simulation but improved to 88.05% in real operation, reflecting a 5.35% gain in energy output. Financial analysis shows that the system achieves payback within 6.8 years, with a levelized cost of energy of 3.43 PKR/kWh and levelized savings of 13.23 PKR/kWh, amounting to cumulative lifetime savings of 898.2 millions PKR. The findings highlight the reliability and profitability of solar PV in Pakistan and demonstrate that integrating simulation and real-time data provides a more accurate basis for investment decisions. This study contributes a practical framework for bridging the gap between theoretical modeling and operational outcomes, offering actionable insights for accelerating the transition to economically viable green energy solutions.

Applications of liquid-cooled mini-channel heat sinks have further increased due to the demand for miniaturization, high efficiency, and high energy density systems. These advanced high heat generating devices require cooling solutions with enhanced and instance performances. Longitudinal vortex generators (LVGs) have the potential to make mini-channel perform thermally better at high heat density and the mentioned fact encourages further investigations. However, innovative shape modifications, parameters and their combinations have not been studied in detail. In the present study, Mini-channels are modified by considering various configurations (co-flow-up, co-flow-down, counter-flow-up, and counter-flow-down) of LVGs. Each channel contains four rows of equally placed LVGs along the side walls. Thermal performance is discussed by analyzing the fluid structure modified due to the induced longitudinal vortices and parameters of LVGS are refined accordingly. The results indicate that the implementation of LVGs improves the heat transfer performance. The most optimized values (138 to 223% enhancement of Num, 41.2 to 46.2% reduction of Rtot) are noted for longitudinal counter-flow-down LVGs (Channel width ratio and attack angle are 0.3 and 45°, respectively). The noted performance evaluation factor (PEC) is 1.43 to 1.54 at Re = 317 to 950. To further understand physics, local heat transfer efficiency of LVG-enhanced mini-channels is derived by the entropy generation of conjugate heat transfer. For indicating the local distribution of irreversible heat transfer losses. It is found that the implementation of LVGs reduces the entropy generation in both fluid and solid regions. Reduction of Sgen,f and Sgen,s are 62% and 27.8%, respectively, than the smooth channels.

Enhancing the flame retardancy and toughness of epoxy thermosets without compromising glass transition temperature (T g) or mechanical strength is a critical challenge. In this study, the graft copolymer, SEBS-g-PEG was prepared by chemically grafting polyethylene glycol (PEG) to the terminal blocks of polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS). These block copolymers (BCPs) along with various loading levels of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) were covalently incorporated into the epoxy thermosets to enhance their properties. The resulting composites exhibited excellent matrix compatibility, achieving up to a 200% improvement in fracture toughness and a 70% increase in flame retardancy at higher DOPO loadings (e.g., 8 wt%) without plasticizing effects. Notably, T g and tensile strength were preserved, enabling balanced high-performance composites.

Ultra-high Molecular Weight Polyethylene (UHMWPE) is a highly versatile polymer known for its exceptional mechanical properties, however, its limited life as an implant material for Total Joint Replacement (TJR) necessitates surface modification to extend its lifespan. This study aims to enhance the surface properties of UHMWPE through application of ceramic coatings. Magnetron sputtering method was used to deposit thin film of white Titania (TiO2) on the material’s surface. To evaluate the surface characteristics, such as surface roughness, uniformity and structure, coated and uncoated samples were analyzed through Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray Diffraction Analysis (XRD). The material performance in relation to biological context was investigated through Contact Angle measurement. A comparative analysis of coated and uncoated samples was then performed. The coated samples showed better wettability compared to uncoated sample. This fact highlights the hydrophilic nature of film. The results of the coated UHMWPE suggest that this surface modification technique could significantly extend the lifespan of UHMWPE implants in TJR, potentially addressing the current limitations associated with their longevity.

Perovskite solar cells (PSCs) are vital for their optical and electrical properties, with lead-based PSCs reaching a remarkable efficiency of 26.1%, while tin-based counterparts achieve 18.71%. Due to lead's toxicity, there's a push for alternatives like tin. However, tin-based PSCs suffer from stability issues and high defect density states, necessitating the development of cost-effective, high-performance, and eco-friendly alternatives. In this study, we designed a hetero-junction architecture using MASnI3-based Perovskite, opti-mized with SCAPs-1D. After exhaustive analysis, our device achieved a power conversion efficiency of 24.18%, with enhanced parameters including Voc of 0.09323V, Jsc of 30.8360 mA/cm2, and FF of 84.10%. Recombination rates, particularly Shockley-Read Hall recom-bination, were significantly reduced. Parametric analyses, encompassing absorber layer thickness, band gap, defect density, doping concentration, and operating temperature, in-dicate potential efficiency enhancements. This underscores the viability of Sn-based PSCs as a cost-effective, efficient, and environmentally benevolent alternative to lead-based counterparts, promising advancements in future research and development efforts.

The performance of Photovoltaic (PV) modules heavily relies on their structural strength, manufacturing methods, and materials. Damage induced during their lifecycle leads to degradation, reduced power generation and efficiency. Mechanical stresses, originating from manufacturing, transportation, and operational phases impose significant loads on PV modules. These in-service loads encompass various environmental forces such as wind, snow, dust, hail, rain, and heat. In-service loads encompass static and dynamic forces such as wind, snow, dust, hail, rain, and heat. Among these factors, the mechanical loads from hail impacts play a crucial role in PV module performance and require a comprehensive investigation. This research focuses on evaluating the impact of hail loads on different PV modules, following international standards like ASTM 1038-10 and IEC-61215-2. The developed simulator effectively assesses the reliability of PV modules. The number of busbars within a PV module was identified as a key factor influencing the module's resilience to hail impacts. Notably, mono-crystalline PV modules exhibited better resistance to hail loads compared to their poly-crystalline counterparts. The PV modules experience micro-cracking due to hail impacts, leading to an efficiency reduction of 4.15% in mono-crystalline modules and 12.59% in poly-crystalline modules. Similarly, the generated power output decreased by 3.3% and 12.5%, respectively, in these module types.

This research paper presents a comprehensive study on the identification of cracks in solar panels using a combination of electroluminescence (EL) and thermal imaging techniques. The EL imaging was utilized to capture the electroluminescent response of the panels, highlighting any irregularities in the cell structure caused by cracks. While thermal imaging was used to identify temperature variations indicative of crack locations due to localized heat dissipation. The results of the study demonstrate the efficacy of each imaging technique in crack detection. EL imaging exhibited high sensitivity to cracks, providing detailed information about the location and extent of the damage. Thermal imaging, on the other hand, revealed temperature differentials in cracked areas. Furthermore, thermal imaging can expediently assess health of solar panels insofar as both methods were successful in identifying major defects in solar panels. In addition, the research paper discusses the advantages and limitations of each imaging technique, providing insights into their applicability in real-world solar panel inspection scenarios. The thermal imaging showed that a temperature difference of ten degree Celsius between average and peak temperature on solar panels showed major cracks or faults in the panel.

Shell and tube heat exchangers (STHX) are the most abundantly used heat exchangers in the industry. Baffles are the most important component involved in improving the thermohydraulic performance of STHXs. In this study, we propose a novel segmented trefoil baffle (STB) formed by imposing trefoil holes on segmental baffles (SGB). Numerical simulations have been conducted using ANSYS FLUENT 19.2 for SGBs, trefoil hole baffles (THB), and STBs at various mass flow rates to compare the heat transfer coefficients, pressure drop, thermohydraulic performance, and shell side flow distribution. Results indicate that for almost the same heat transfer coefficient, the pressure drop is significantly less for the STBs compared with the SGBs. A study of the flow field revealed that large dead zones, typical of SGBs, reduce significantly when STBs are used. Similarly, the recirculation zones, reported for THBs also decrease by incorporating the STBs. The thermohydraulic performance is enhanced by 41% and 235% compared to SGBs and THBs respectively by using the STBs. An increase in the number of baffles from 6 to 10 further enhanced the advantage of STBs over the segmental baffles from 41% to 57%. The inclusion of baffles to shell and tubes clearances does not affect the superior thermohydraulic performance of STBs over SGBs.

Eutectic Phase change material (EPCM) absorbs or releases heat energy during phase transition at a uniform or narrow range of temperature. A simple and easy T-history method (THM) was used to determine the melting and crystallization temperatures and charging and discharging durations of the EPCM. The THM was utilized to evaluate the thermo-physical properties of different salt hydrates, paraffin, and non-paraffin compounds. The Glauber salt (GS) was selected as the main compound; however, other salts were added to make it eutectic. Three samples with different chemical compositions (wt.%) were prepared and tested to find their melting and crystallization temperatures and charging and discharging times using the T-history method. The charging times and melting temperatures of the samples IA, IIA, and IIIA were 45, 34, and 26 minutes and 23.4, 14.3, and 8.2 °C, respectively. The discharging times and freezing temperatures of the samples IA, IIA, and IIIA were 13, 14, and 23 minutes and 18.7, 16.2, and 8.6 °C, respectively. The EPCM was selected of its high heat capacity and thermal conductivity, eco-friendliness, low cost, high charging, and discharging duration, and easy operation are developed and optimized depending on the applications.

The purpose of this study is to evaluate the performance of hot mix asphalt (HMA) prepared with coal bottom ash (CBA) as an alternative mineral filler. In this study, the effect of CBA on rutting, stiffness and fatigue resistance was experimentally evaluated. Combinations of conventional filler (stone dust) with different percentages of CBA (at 1.5%, 3%, and 4.5% by volume) were adopted. The HMA samples were prepared and tested using the Marshall mix design method. Following the Asphalt Institute MS-2 and the Pakistani National Highway Authority (NHA) General Specifications, sixty samples of HMA were compacted; stability tests at varying bitumen contents (3.5%, 4.0%, 4.5%, 5.0%, and 5.5%) were used to determine the optimum bitumen content (OBC) in the mixture for each percentage of CBA in the filler. For 0%, 1.5%, 3%, and 4.5% CBA, the optimum bitumen contents of 4.27%, 4.47%, 4.53%, and 5.0% were obtained, respectively. They were used throughout the study. Three samples with the optimum binder content were made for each of the four analysed CBA proportions. The wheel tracker test was run on 12 OBC samples, and the dynamic modulus test was run on 12 OBC samples. The Marshall stability and flow test results showed that the samples prepared with 3% CBA as filler and an OBC of 4.53% satisfied the NHA requirements for flexible pavement. It was noted that CBA greatly improves the rutting resistance and stiffness of asphalt mixtures. It also improved the fatigue life. Therefore, adding up to 3% CBA by volume to stone dust used as filler in asphalt concrete can minimize the need for stone dust and provide a suitable method of CBA disposal.

Tackling water scarcity is a significant challenge due to the rapid increase in the global population, which is raising concern for the supply of fresh water. high demand of fresh water leading to a failure in meeting the demand for fresh water. This study aims to investigate the feasibility of an efficient single-slope solar still with an aluminum-finned plate absorber and internal and external reflectors to address water scarcity. Energy, exergy, economic and environmental analyses (6E) were undertaken to deeply analyze its impact on the environment. The maximum energy and exergy efficiency achieved was 60.19% and 21.57%, respectively, at a 2cm depth. The use of both external and internal reflectors assisted in the highest productivity of 7.02 liters. The cost of 0.033$/liter was obtained for a lifetime of 10 years for the optimal system. The payback time in terms of energy and exergy for the optimal system is 0.88 and 2.23 years, respectively. Furthermore, sustainability and sensitivity (2S) analysis were also performed to assess the system's current and future feasibility. The total price for carbon dioxide mitigation during the solar still lifetime was $346.7, which represents the cost saving achieved with the installation of the optimal system.

There is significant potential for agricultural involvement in the production and consumption of solar, wind, geothermal, and biomass energy. Renewable resources are abundant and widely distributed throughout the India. A number of commercial technologies are available to harness these resources, and with appropriate support, additional technologies – some potentially paradigm-shifting – could be brought to market. Renewable energy and farming are winning combination. Wind, solar, and biomass energy can be harvested forever, providing farmers with a long-term source of income. Renewable energy can be used on the farm to replace other fuels or sold as a “cash crop.”While the global economy maintains its low-level growth, the Indian economy continues on its high growth trajectory. The year 2016-17 has seen a paradigm shift in the way India’s economy will function by focusing on laying the infrastructure for widespread inclusion of all economic activity on the digital platform. Power sector plays a vital role in the growth of Indian economy and it is growing at rapid pace. Renewable technologies are now supplying or supplementing many on-farmenergy requirements, from water pumping to space heating. Increasingly, farmers and ranchers are selling energy (e.g., electricity generated from wind turbines, biofuels, and products from biomass). This is contributing to greater energy security in agriculture through increased diversity of energy sources, more self-supply of energy, and reduced environmental impact The total installed capacity has reached to 310 GW with generation mix of Thermal (69.4%), Hydro (13.9%), Renewable (14.8%) and Nuclear (1.9%). It is evident that the renewable power has secured 2nd position after Thermal and is spreading its wings rapidly in India.

Deployment of solar photovoltaic panels are significantly rising to tackle adverse effects of climate change however, factors affecting output need to be categorized in addition to latitude angle and space. It is important to consider the atmospheric impact which can drastically change output power of solar panels. This study covers dust accumulation of soil, sand and ash at variable weights to foresee its effects on panel power output. Mixtures of these particles at multiple constituents were also analyzed. Experimental results indicated that clean panel gives maximum power output of 21.37W and exergy efficiency of 7.96% whereas ash accumulation showed worst results of 2.88W power output and 1.07% exergy efficiency at 700W/m2 and 50g dust accumulation. Other parameters like energy destruction, exergy losses and sustainability index were also analyzed. Trends have been illustrated in graphs along with the change in solar intensity and dust accumulations.

The progress in industry of a country is linked with per capita energy consumption. Conventional energy sources are becoming extinct because of their exhaustive use and causing serious environmental damage. Renewable energy sources are replacing existing conventional power plants operated on fossil fuels. Solar energy is a renewable energy sources that has various advantages over other conventional and renewable energy sources. The source of solar energy is free and unexhausted. Solar energy can be extracted in different forms: solar thermal, solar photovoltaic, and solar lighting. This chapter discusses the planning and modeling of photovoltaic-based solar energy systems. Solar PV systems consist of solar PV modules as a source of energy, DC-DC power converters to boost up or buck down the voltages, and inverters to convert the DC power of PV modules into AC power to manage the load or feed the grid. The performance of the solar cells depends upon environmental parameters like solar irradiance and cell temperature. These parameters are not constant; they vary with the change in sun position and the cloudy seasons. The solar irradiance determines the short circuit current of the solar cell and the cell temperature determines the open-circuit voltage. The change in any of these parameters causes a change in power.

A new axisymmetric CFD model capable of describing pumping loss is proposed for free piston Stirling engine. Inclusion of clearance seals, bounce space, heater, cooler, and regenerator in a single model is the unique strength of this work. For transient simulation of engine, dynamic mesh was utilized for catering needs of moving boundaries. The model was validated with 12.5 kW component test power converter and successfully predicted indicated power, efficiency, pressure amplitude, pressure drop, and gas temperature in expansion and compression space at different piston amplitudes with 6% maximum deviation. The results showed that the heat exchange at heater and cooler was minimized at each flow reversal and was strongly influenced by oscillating gas-flow rate. The results also present optimum displacer and piston seal clearance at different charge pressure and operating frequencies. The displacer seal clearance could be increased up to 125 ?m without compromising power, however, engine output was severely affected with increasing piston seal gap.

Despite the wide applications of multi-effect vapor absorption systems, their energy requirement is relatively higher. Also, their exergy analyses found in the literature reveal that the exergy destruction rate at the absorber is quite significant and has the potential for improvement in its energy efficiency. In this work, the exergy destruction rate at the absorber is minimized using the penalty factor method against the optimized generator temperature of the double-effect vapor absorption system by considering absorber, evaporator, and condenser temperatures into consideration. Modeling of the double-effect vapor absorption system was performed using a thermodynamic toolbox in SIMULINK. The present model employed a refrigerant heat exchanger to enhance the system cooling capacity. The liquid-vapor ejector valve at the absorber also improved the mixing of the solution and refrigerant vapor resulting in lower irreversibility of the system. Results show that the coefficient of a performance increase by 2.4% with refrigerant heat exchanger and exergy loss at absorber decrease by 9.4% with ejector. The optimum performance was seen at the condenser and evaporator temperatures of 308.8 K and 278.1 K, respectively with an 8.2% improvement in exergetic efficiency. Finally, it is concluded that the multi-effect absorption system shows better performance by minimizing the irreversibility.

Multiphase flow occurs in almost all HVAC and refrigeration systems.In this work, numerical simulations of condensation heat transfer phenomenon of R134a refrigerant inside smooth horizontal tube is carried out in order to better visualize the flow behavior and analyze heat transfer characteristics of R134a refrigerant. For multiphase flow analysis of R134a refrigerant, k-omega shear stress transport (SST) turbulence model is used which is well suited for simulating flows in the viscous sub-layer. For predicting and analyzing the heat transfer characteristics, Heat and mass transfer model(Lee Evaporation-Condensation Model) is used for internal flow condensation to occur.Convective heat transfer coefficient is determined throughout the tube using surface integral method which matched with the convective heat transfer coefficient obtained using experimental data. Volume fractions of both the liquid and vapor phases are obtained at both the symmetrical and cross-sectional planes which indicated that homogeneous condensationoccurred resulting in mist flow which later on changed to stratified and stratified wavy flow. The temperature distribution obtained for the two phase flow (liquid and vapor) showed that the refrigerant was initially in dry saturated statewhich then condensed into two phase mixture (liquid and vapor) as the condensation process proceeds downstream. The results indicate that the k-omega (shear stress transport) turbulence model predicts the multiphase flow characteristics better than the k-epsilon turbulence model.

In this manuscript, a numerical investigation on the temperature gradient of a magnetic refrigerator using different geometric configurations of a parallel plate regenerator is presented. The parallel plate regenerator is made up of gadolinium (Gd) as a magnetocaloric material with rectangular channels. The parallel plate regenerator is modeled and numerically investigated for 3D conjugated fluid convection and conduction heat transfer using Ansys Fluent. Two piston-cylinder displacers drive water as the working fluid through the regenerator loop. The hot and cold end heat exchangers are treated with the ε-NTU method. The effect of changing the parallel plate regenerator’s dimensional parameters on temperature span is examined against the utilization factor of 0.1, keeping the regenerator’s porosity constant. The maximum temperature span is predicted by comparing simulated parallel plate magnetic regenerators for two diverse sets of dimensional parameters and surface areas is 36.5 K for magnetic field intensity of 0.8 T.