Diesel engines have extensive use in vehicles, power plants, and agriculture, but they pose significant challenges due to both regulated and unregulated emissions. As fossil fuel supplies diminish and pollution levels increase, it has become crucial to shift from conventional fuels to biodiesel and alternative additives. This experimental study investigates the emission and performance characteristics of a water‐cooled, three‐cylinder, four‐stroke compression ignition engine operating on blends of Jojoba methyl ester (JME) combined with additives such as carbon nanotube (CNT). JME was mixed with pure diesel in concentrations of 5% and 15% by volume, creating blends referred to as J5 and J15. CNT was added to these blends at a concentration of 20, 40, and 60 ppm. Emission and performance metrics were evaluated across engine speeds varying from 1200 to 2200 rpm. The findings revealed significant improvements, with brake thermal efficiency (BTE), brake power (BP), and torque increasing by 6.7%, 3.8%, and 3.8% respectively. A 2.6% reduction in brake‐specific fuel consumption (bsfc) was observed at 1600 rpm with the J5CNT60 blend. The introduction of Jojoba biodiesel into neat diesel resulted in reductions of 12.8%, 14.56%, 15.25%, and 7.27% in nitrogen oxide (NO _x ), carbon monoxide (CO), carbon dioxide (CO ₂ ), and unburned hydrocarbon (UHC) emissions, respectively. Although Jojoba biodiesel resulted in a slight increase in smoke opacity (SO) emissions by less than 1%, the addition of CNT led to a 2% decrease in SO emissions at 2000 rpm.

This experimental study investigates the impact of biodiesel derived from Jatropha oil and multiwalled carbon nanotubes (CNTs) on the performance and emissions of a diesel engine. The analysis involved five fuel conditions: pure diesel (D), diesel blended with 50% biodiesel (DB50), diesel blended with 80% biodiesel (DB80), diesel blended with 50% biodiesel and CNTs (DB50C), and diesel blended with 80% biodiesel and CNTs (DB80C). The results indicate that biodiesel blends, particularly those enhanced with CNTs, significantly improve fuel efficiency and engine performance. Blends with additives (DB50C and DB80C) exhibited higher brake power (BP) and lower brake‐specific fuel consumption (BSFC) across various engine speeds, indicating more effective energy conversion and better fuel economy. Moreover, emissions analysis revealed that biodiesel blends with CNTs significantly reduce harmful emissions. Emissions of carbon monoxide (CO), unburned hydrocarbons (UHCs), and nitrogen oxide (NO _x ) were consistently lower for DB50C and DB80C compared to D. The most notable reduction of 23.9% in NO _x emissions occurred at an engine speed of 2200, while CO and UHC emissions were reduced by 17.8% and 15.4%, respectively, at engine speeds of 1600 rpm. These findings suggest that the use of biodiesel with CNT additives not only increases combustion efficiency but also contributes to cleaner engine operation. This study emphasizes the potential of biodiesel, especially when combined with advanced nanoparticles, as a practical and environmentally friendly alternative to conventional diesel fuel.

An experiment was conducted to explore the impact of cooling air in a portable bladeless pedestal fan using Peltier modules. Traditional cooling methods face challenges of high energy consumption, motivating the need for innovative solutions. This study hypothesized that integrating Peltier modules into a pedestal fan could significantly enhance cooling efficiency while conserving energy. Investigating the shift from traditional to renewable energy systems for air conditioning (A/C) and ventilation is crucial for achieving sustainability and energy conservation. To meet the comfort standards set by ASHRAE, a study was carried out to design, construct, and assess the cooling efficiency of a bladeless pedestal fan employing Peltier modules. This study also examined how Peltier modules influence the efficiency of a conventional pedestal cooling fan. The experimental study was held in a 4 × 4 m room using two, four, six, and eight Peltier modules at external temperatures ranging from 43°C to 45°C, with indoor starting temperatures of 37°C. Each setup was tested three times and each experimental condition was tested for 60 min, with data recorded at 10‐min intervals. The Peltier effect was utilized to cool water, which in turn cooled the air. The comfort zone was subsequently created using this cooled air. A regression analysis was employed to validate the results, with the cooling performance evaluated using standard error and confidence intervals. The energy savings were estimated by comparing the power consumption of the Peltier module‐based fan to that of conventional pedestal fans and A/C units. The temperature reduction achieved was 4%, 12%, 18%, and 22% with the use of two, four, six, and eight Peltier modules, respectively. The energy analysis indicated significant savings, suggesting that the proposed Peltier‐based bladeless pedestal cooling fan could potentially save over 2000 MW of energy nationwide if it replaced traditional pedestal fans.

In recent years, plant fibers have attracted increasing attention due to their numerous advantages, including their renewability, low cost, biodegradability, and reduced environmental impact. Owing...

The performance and emission characteristics of a water‐cooled, four‐stroke, three‐cylinder compression ignition (CI) engine were examined in this work in relation to the synergetic effects of titanium dioxide (TiO ₂ ) nanoparticles and Jatropha methyl ester (JME) biodiesel. A variety of fuel blends, including B10 and B20 (10% and 20% JME by volume), as well as their corresponding nanoparticle‐enhanced versions (B10T30, B10T60, B10T90, B20T30, B20T60, and B20T90), were used in the experimental testing. Pure diesel (D) was used as the baseline. In order to assess important performance parameters, including torque, brake‐specific fuel consumption (BSFC), brake thermal efficiency (BTE), and emission parameters like nitrogen oxide (NO _x ), hydrocarbons (HC), carbon monoxide (CO), and smoke opacity, the engine was operated under constant full load conditions, with the speed adjusted between 1200 and 2200 rpm in increments of 200 rpm. The findings show that adding TiO ₂ nanoparticles greatly enhances engine performance. When compared to diesel, the B20T90 and B10T90 showed the most substantial gains, with BTE increases of up to 6.2% and BSFC reductions of 3.4%. All TiO ₂ ‐enhanced blends showed much lower CO and smoke emissions, suggesting cleaner burning though HC emissions increased at higher nanoparticle concentrations, possibly due to agglomeration effects. However, because of excessive oxygen availability and higher combustion temperature, there was an increase in HC and NO _x emissions. Overall, the results show that JME and TiO ₂ work in combination to improve fuel economy and lower particle emissions. If the issue of cost‐effective nanoparticle sourcing is resolved, these fuel blends—in particular, B10T90 and B20T90—show potential for short‐term benefits in controlled laboratory conditions, but substantial further work is required on long‐term durability, regulatory pathways, and cost‐benefit ratios compared to existing aftertreatment systems such as SCR and DPF, to assess their viability for sustainable diesel engine operation in the industrial and transportation sectors.

This study presents an experimental and numerical investigation of single-stepped-lap joints (SSLJs) and single-lap joints (SLJs) made from carbon/epoxy composites (CFRP), focusing on the combined effects of joint geometry and substrate thickness (2.0 and 4.0 mm) on joint strength and failure mechanisms. The main contribution of this work lies in the systematic assessment of these two parameters and in the use of a coupled LaRC05/XFEM-CZM framework to provide a comprehensive description of damage evolution by simultaneously accounting for adhesive failure and damage initiation in the composite substrates. CFRP plates were CNC-machined to obtain the required joint geometries, adhesively bonded using a structural epoxy, and subjected to tensile testing. A three-dimensional finite-element model was developed in Abaqus, incorporating cohesive zone modeling (CZM) for the adhesive and the LaRC05 criterion coupled with the extended finite element method (XFEM) for the composite substrates. The numerical predictions showed very good agreement with the experimental results. The SSLJ consistently outperformed the conventional SLJ, with the 2.0 mm configuration reaching an ultimate failure load of 7584 N compared with 6852 N for the SLJ, corresponding to an improvement of 10.7%. This improvement is attributed to improved load-path alignment and reduced secondary bending effects. Conversely, increasing the substrate thickness from 2.0 to 4.0 mm reduced the ultimate failure load by 4.13% for the SSLJ and 6.76% for the SLJ. Although the thicker substrate increases the overall flexural stiffness, the associated modification of load-path eccentricity intensifies secondary bending and combined stresses near the overlap ends. The coupled numerical framework successfully reproduced the global experimental response and predicted the progression of adhesive and localized substrate damage. Overall, the 2.0 mm SSLJ exhibited the best mechanical performance among the investigated configurations.