RESUMO
Petroleum fuels are commonly used for automobiles. However, the continuous depletion and exhaust gas emission causes serious problems. So, there is a need for an alternative eco-friendly fuel. Biodiesel is a type of fuel manufactured through a process called transesterification, which involves converting vegetable oils into a usable form. The process parameters of the transesterification process were optimized using the Taguchi method to achieve maximum biodiesel yield. However, the main problem of biodiesel is its high cost which could be reduced by using low-cost feedstock. To address this challenge, biodiesel (BCFAD) is derived from coconut fatty acid distillate (CFAD), a by-product obtained from refining coconut oil. This work uses BCFAD and BCFAD with Alumina nanoparticles as fuels. Alumina nanoparticles in the mass fraction of 25 ppm, 50 ppm, and 100 ppm are dispersed in BCFAD. The investigation results reveal an increase of 6.5% in brake thermal efficiency for BCFAD with 100 ppm nanoparticles when compared to BCFAD. There is a reduction of 29.29% of hydrocarbon and 34% of Carbon monoxide emissions with BCFAD100 in comparison with diesel. However, there is a marginal increase in NOx emission with the increase in nanoparticles. The heat release rate and cylinder pressure of BCFAD100 are comparable to diesel fuel. It was concluded that the utilization of BCFAD with a nanoparticle dispersion of 100 ppm is suitable for direct use as fuel in diesel engines.
RESUMO
The present study aims to examine the characteristics of a composite material composed of glass/madar fibers and porcelain particles, which are reinforced with epoxy. A compression molding technique achieves the fabrication of this composite. A comprehensive characterization was conducted by employing a mixture of analytical techniques, including X-ray Diffraction (XRD), mechanical testing, Scanning Electron Microscopy (SEM), Dynamic Mechanical Analysis (DMA), and Thermogravimetric Analysis (TGA). The composition of the composite was determined using X-ray diffraction (XRD) analysis, which demonstrated the successful integration of porcelain fillers. The material exhibited notable mechanical properties, rendering it appropriate for utilization in structural applications. The utilization of SEM facilitated the examination of the microstructure of the composite material, thereby providing a deeper understanding of the interactions between the fibers and the matrix. DMA results revealed the glass/madar composite contained 4.2% higher viscoelastic properties when the addition of porcelain filler, thermal stability was improved up to the maximum temperature of 357 °C. This study provided significant insights into the properties of a hybrid epoxy composite consisting of glass/madar fibers reinforced porcelain particles.
RESUMO
The spray characteristics of a fuel greatly influence the combustion as it affects the formation of an air-fuel mixture, which directly impacts the performance and emissions of the engine. This study investigates the physical injection spray characteristics of biofuels to optimize the engine operating parameters for their effective utilization. For the analysis of the spray characteristics of pure diesel (D100), 80% diesel-20% biodiesel (D80B20), 80% diesel-10% biodiesel-10% pure ethanol (D80B10E10), and 80% diesel-10% biodiesel-10% hydrous ethanol (D80B10HE10) are investigated. Computational Fluid Dynamics (CFD) modeling of a constant volume chamber under non-evaporative conditions is performed to conduct numerical analysis. The chamber pressure of 2 and 2.5 MPa and nozzle injection diameter of 0.126 mm, 0.15 mm, and 0.2 mm are considered to conduct the simulations. The variation in spray penetration length is analyzed and discussed for the injection of different fuel blends at different initial conditions. It is observed from numerical results that the high-density fuel blend D80B20 has a penetration length of 10.695% and 15.805% higher than pure diesel and D80B10HE10 blends, respectively. For pure diesel, with an increase in nozzle diameter from 0.126 mm to 0.15 mm and 0.2 mm, the penetration length is increased by 20% and 32%, respectively, and with an increase in pressure from 2 MPa to 2.5 MPa, penetration length is decreased by 14.62%. From this study, it can be concluded that biofuels like biodiesel and hydrous ethanol can be used with diesel in blended form over pure ethanol. Compared to pure ethanol, hydrous ethanol gives cost benefits and better spray characteristics.
RESUMO
The strength of rock under uniaxial compression, commonly known as Uniaxial Compressive Strength (UCS), plays a crucial role in various geomechanical applications such as designing foundations, mining projects, slopes in rocks, tunnel construction, and rock characterization. However, sampling and preparation can become challenging in some rocks, making it difficult to determine the UCS of the rocks directly. Therefore, indirect approaches are widely used for estimating UCS. This study presents two Machine Learning Models, Simple Linear Regression and Step-wise Regression, implemented in Python to calculate the UCS of Charnockite rocks. The models consider Ultrasonic Pulse Velocity (UPV), Schmidt Hammer Rebound Number (N), Brazilian Tensile Strength (BTS), and Point Load Index (PLI) as factors for forecasting the UCS of Charnockite samples. Three regression metrics, including Coefficient of Regression (R2), Root Mean Square Error (RMSE), and Mean Absolute Error (MAE), were used to evaluate and compare the performance of the models. The results indicate a high predictive capability of both models. Notably, the Step-wise model achieved a testing R2 of 0.99 and a training R2 of 0.988 for predicting Charnockite strength, making it the most accurate model. The analysis of the influential factors indicates that UPV plays a significant role in predicting the UCS of Charnockite.
RESUMO
Numerous countries are investigating alternative fuel sources in response to the escalating issue of energy inadequacy. Using environmentally sustainable biodiesel as a potential alternative to fossil fuels, particularly from waste sources, is a developing prospect. This study aims to examine the feasibility of utilizing industry leather waste as a diesel fuel substitute. Traditional transesterification was used to obtain methyl ester out of leather waste. After processing, 81.93% of methyl ester was produced. Bio-silica (Bio-Si) is used as a fuel additive to enhance combustion and decrease emissions. This work utilized a leather industry waste fat biodiesel (LIWFB), LIWFB blend (B50), LIWFB blend with Bio-Si nanoparticles (B50Bio-Si50, B50Bio-Si75, and B50Bio-Si100 ppm) to analyze the engine outcome parameters at standard operating conditions. Experimental results revealed that adding Bio-Si in the biodiesel blend increased thermal brake efficiency (BTE) but was lower in diesel fuel. The biodiesel blends reduced NOx emissions more than Bio-Si nanoparticle blends. Furthermore, the smoke opacity was reduced by 31.87%, hydrocarbon (HC) emissions were reduced by 34.14%, carbon monoxide (CO) emissions were decreased by 43.97%, and oxides of nitrogen (NOx) emissions were slightly increased by 4.45% for B50Bio-Si100 blend compared to neat diesel. This investigation determined that all the emissions remained lower for all combinations than neat diesel, with a small increase in NOx emissions. Therefore, the LIWFB blend with Bio-Si nanoparticles was a viable diesel fuel alternative in diesel engines.
RESUMO
The objective of the present investigation is to enhance the performance of diesel engine using Capparis spinoza fatty acid distillate biodiesel (CFAB100) at various compression ratios. The experiments were carried out at compression ratios of 16.5:1, 17.5:1, 18.5:1, and 19.5:1. It was noted that an increase in compression ratio from 16.5 to 18.5 resulted in better engine characteristics for CFAB100 and reduced at compression ratio 19.5. Brake-specific fuel consumption of CFAB100 decreased from 0.42 to 0.33 kg/kWh with an increase in compression ratio. The brake thermal efficiency of CFAB100 at a compression ratio of 16.5 is 29.64% lower than diesel, whereas it is 11.32% low at a compression ratio of 18.5. The brake thermal efficiency of CFAB100 is 26.03% higher at a compression ratio of 18.5 compared to 16.5. Due to shorter ignition delay and reduced premixed combustion, the net heat release rate of CFAB100 is lower than diesel at all compression ratios. The peak cylinder pressure for diesel is 56.21 bar, and CFAB100 at compression ratios 16.5, 17.5, 18.5, and 19.5 were 52.36, 55.12, 61.02 and 58.25 bar at full load condition. CFAB100, at a compression ratio of 18.5, had the highest nitrogen oxide emissions (2400 ppm). Carbon monoxide, unburnt hydrocarbon, and smoke showed an average reduction of 46.58%, 40.68%, and 54.89%, respectively, when the compression ratio varied between 16.5 and 19.5. At an optimum compression ratio of 18.5, the CFAB100 resulted in improved performance and emission characteristics that can replace diesel to a possible extent.
RESUMO
Beam-column joints are crucial load transmission zones because they face concentrated forces from both the beams and the columns. High shear and axial stresses caused by these concentrated forces in the area of the joint may result in decreased joint strength. This article proposes a new beam-to-column connection developed for precast concrete-resisting frames. Concrete mixtures are enhanced mechanically by adding nano silica as it increases compressive strength, flexural strength, and abrasion resistance. Within the concrete, it creates a solid, gel-like matrix that fills voids and strengthens the whole construction. In this study, three reinforced concrete beam-column joint specimens were cast with fly ash, the other three with nano-silica and fly ash, and one sample with nano-silica and a control mix without admixtures was cast. Specimen cast using fly ash and nano-silica is subjected to cyclic loading after 28 days of curing. A load capacity of 100 kN was imposed on the column during testing. It was observed that a gradual increase in fly ash decreased the compressive and flexural strength of the beam-column joints. This decrease in strength was addressed by adding 2.5% nano-silica. Nano silica acts as a nucleus to bond tightly with cement particles during hydration. The results showed that the flexural strength equivalent to that of a controlled specimen can be achieved by adding nano-silica at 2.5% and fly ash at 60%. The highest loading of 38.1 kN can be applied to the specimen with nano-silica without fly ash. Although a higher axial compression ratio can improve the bearing capacity and initial stiffness, it can also reduce deformation capacity and flexibility.
RESUMO
Bioactive substances such as phenolic compounds, antioxidants, and antibacterial agents are found in natural fibres. In this study, banana fibre was extracted from the trunks of banana plants. Antibacterial activity, FTIR, XRD, and SEM analysis were performed to characterize the banana cellulose fibre, and also raw and alkali-treated banana fibre composite was fabricated with an epoxy matrix. Results of the antibacterial analysis indicate that this banana cellulose fibre strongly impedes bacterial growth with elevated inhibitory zones. The primary peaks observed at 1170 cm-1 and 1426 cm-1 by FTIR analysis correspond to C-O stretching, O-H bending, aliphatic ether, secondary alcohol, and carboxylic acid. The morphological analysis reveals the fibre quality, and the EDX analysis confirms the elements present in the banana cellulose fibre. The XRD results demonstrated a more significant proportion (76.8%) of the amorphous region. This study indicates that banana cellulose fibre could be a promising source of antimicrobial compounds. In addition, the mechanical properties of alkali-treated banana fibre composite were preferable to raw fibre composite by an average of 3% for this banana fibre composite. As a result, this composite can be used to manufacture automobile interior components, as it can reduce the sanitizing periods of interior components during winter months.
