This paper investigates the tensile properties of jute-reinforced composites fabricated using stereolithography (SLA) 3D printing. Tensile tests were conducted using dog-bone tensile specimens following ASTM D638 Type IV specifications. Additionally, the study explores the effect of layer thickness on the tensile properties of the 3D-printed composite material, examining four different layer thicknesses: 0.025 mm, 0.05 mm, 0.075 mm, and 0.1 mm. The findings revealed that the tensile strength of the 3D-printed jute-reinforced composites increased with the printing layer thickness, reaching its maximum at a layer thickness of 0.1 mm. This represents an enhancement of approximately 84% compared to pure resin. Examination of the fiber–matrix interface under an optical microscope revealed a wavy pattern, suggesting that the interface may act as a mechanical interlock under tensile loads, thereby significantly enhancing tensile strength. The strength of the 3D-printed jute-reinforced composites was found to be comparable to that of glass fiber mat epoxy composites. This demonstrates that 3D SLA-printed jute-reinforced composites offer a promising avenue for producing next-generation composites that are typically challenging to manufacture using traditional fabrication techniques.

The growing interest in sustainable and biodegradable materials has prompted significant attention towards natural fiber-reinforced composites (FRC) due to their lower environmental impacts. In a similar sustainable vein, this study fabricated composite materials utilizing bagasse fibers with the 3D SLA (Stereolithography) printing method. To start with, a novel fiber extraction process was adopted for extracting fiber from the bagasse stem in three distinct methods (Process-1, Process-2, and Process-3). The fiber extraction process includes washing, sun-drying, manual collection of rind fibers, immersion of rind fibers in NaOH at specific concentrations for specific durations, combing, and drying. In Process-1, the rind fibers were immersed in 5% NaOH for 15 h, while in Process-2 and Process-3, the rind fibers were immersed in 1% NaOH, but the soaking time varied: 25 h for Process-2 and 18 h for Process-3.for 25 h, and in Process-3, the rind fibers were immersed in 1% NaOH for 18 h. The resulting bagasse fibers underwent comprehensive property assessment with a focus on functional group analysis, diameter measurement, and tensile strength assessment. Subsequently, these fibers were used to fabricate composite materials via the 3D SLA printing technique after being treated in a NaOH solution. The Fourier Transform Infrared (FTIR) Spectroscopy results clearly showed that a fraction of hemicellulose and lignin was removed by NaOH, resulting in improved tensile strength of the bagasse fibers. Three-dimensional-printed composites reinforced with bagasse fibers extracted through the P1 method showed the highest improvement in tensile strength (approximately 70%) compared to specimens made from pure resin. The lack of pores in the composite and the observable fiber fracture phenomena clearly indicate that 3D printing technology effectively enhances the quality of the interface between the fiber and the matrix interfacial bonding, consequently resulting in improved tensile properties of the composites. The 3D-printed composites reinforced with bagasse fiber showcased impressive tensile properties and provided solutions to the limitations of traditional composite manufacturing methods. This sets the stage for developing innovative composite materials that combine natural fibers with cutting-edge fabrication techniques, offering a promising path to tackle present and future economic and ecological challenges.

Numerous studies have examined rattan and date palm fibers separately, but none have combined both fibers in a single composite. This research focuses on creating novel hybrid composites using untreated and treated rattan and date palm fibers. Fibers were treated with 3%, 4%, and 5% NaOH solutions. Fiber diameters were measured microscopically. The NaOH treatment enhanced the tensile strength of the fibers. Untreated rattan, midrib, and spadix stem fibers exhibited tensile strengths of 18, 57, and 37 MPa, respectively. Polyester was used as the matrix, combined with fibers in weight fractions of 70 : 30, 75 : 25, and 80 : 20. All composites were made for 1 : 1 rattan–midrib and 1 : 1 rattan–spadix stem fibers. Composites containing 20% treated rattan–midrib fibers displayed the highest tensile and flexural strengths, measuring 13 and 39 MPa, respectively. Meanwhile, rattan–spadix stem composites achieved the highest tensile strength of 14 MPa at 30% treated fiber loading, and the highest flexural strength of 28.91 MPa at 20% fiber wt.%. Additionally, SEM images of the tensile fracture surfaces revealed voids, cracks, and impurities. The goal was to develop a new composite that provides a low cost, structurally sound, and environmentally friendly strong material suited for industrial, construction, and aviation applications.

In the era of rising atmospheric pollution and carbon dioxide emissions, environmentally sustainable energy sources are essential. This study seeks to address this challenge by examining the potential of biofuels, namely biodiesel derived from discarded waste cooking oil. The primary objective was to employ substantial quantities of wasted cooking oil, often generated by households and companies, in order to produce a biodiesel substitute that has a diminished environmental footprint in comparison to conventional diesel fuel. The procedure involved the synthesis of biodiesel through the transesterification of waste cooking oil samples, utilizing Methyl alcohol (CH3OH) and Sodium hydroxide (NaOH) as a catalyst. The collected biodiesel samples were analyzed for important parameters, such as kinematic viscosity, flash point, and density. The kinematic viscosity values for the 10th, 20th, and 30th samples were 5.59 centistokes, 5.46 centistokes, and 4.91 centistokes, respectively. The flash points were determined to be 164.4 °C, 165.4 °C, and 148.4 °C, with densities of 0.8889 g/cc, 0.8891 g/cc, and 0.8891 g/cc, respectively. This study conducts a comprehensive examination and comparison of the characteristics of several biodiesel samples to ascertain the most advantageous choice. Moreover, a comparative assessment is carried out to determine the environmental benefits of the biofuel produced, as compared to conventional diesel. The findings offer crucial perspectives for the discourse on sustainable energy sources, emphasizing the potential of utilizing waste cooking oil-derived biodiesel as a viable and eco-friendly alternative to fossil fuels. By transforming waste cooking oil into biodiesel and carefully assessing its properties during synthesis, this research takes an innovative method.

This study presents the computational fluid dynamics (CFD) driven design and optimization of an intake manifold for a high-performance, restrictor-limited single-cylinder engine. The primary objective was to minimize pressure loss and maximize airflow velocity under the stringent constraint of a 20 mm inlet restrictor. SolidWorks was used for modeling, and ANSYS Fluent was used for simulation. The designs were tested at mass flow rates of 0.0732, 0.0852, and 0.0952 kg/s. The results showed that Design Model 5 performed better than the others, achieving airflow velocities of 220.6, 251.4, and 281.2 m/s, which is 4 to 9% higher than competing models. It also reduced pressure drop by over 69% lower than the other design models, measuring 572.02, 725.49, and 862.48 Pa for the respective mass flow rates. Mesh independence was confirmed with a 5 mm element size, and validation against previous studies indicated less than 0.2% deviation in pressure and velocity predictions. The optimized design’s strong performance stems from smooth airflow with minimal vortex formation demonstrates a significant enhancement in volumetric efficiency for restrictor-limited engines. This study provides a validated CFD framework for designing high-efficiency intake systems under strict flow constraints.