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While the storage, gas grid replenishment and transportation sectors look to be favourable to hydrogen replacing or supplementing current infrastructures, there are still some unanswered problems about the electricity production sector. The research answered the question of why hydrogen import costs are important for the development of a viable hydrogen economy in Japan. The widespread COVID-19 epidemic and political instability worldwide caused a significant transformation in the world's fuel market. The costs of hydrogen energy, hydrogen transportation and carbon trading are modelled. [Extracted from the article]

The primary aim of the present study is to assess the stability and efficacy of hybrid nanocellulose (CNC) and copper (II) oxide (CuO) nanoparticles when integrated into engine oil as a lubricant for piston ring-cylinder liner applications. The assessment of system stability was conducted by employing zeta potential measurements. Furthermore, the coefficient of friction and specific wear rate were determined by using hydrodynamic lubrication in circumstances characterised by high speed and low load, as well as boundary lubrication in situations characterised by low speed and high load. The trials used a specially constructed friction and wear testing device miming the contact geometry between piston rings and cylinder liners in an internal combustion engine. Alongside SAE 40 oil, several nanoparticle concentrations (0.1%, 0.3%, 0.5%, 0.7%, and 0.9% added to SAE 40) were examined. The stability of the nanolubricant increased from 0.1% to 0.5% concentration and then declined at 0.9% concentration, according to the zeta potential data. The graph showed that the 0.5% concentration of the nanolubricant had the highest mean zeta potential, indicating exceptional stability. The CNC-CuO nanolubricants showed notable reductions in the friction coefficient regarding tribological performance. The friction coefficient reduced between 33% and 44% in mixed lubrication and 48% and 50% in boundary lubrication. There was a 9–13% decrease in the friction coefficient when hydrodynamic lubrication was used. The CNC-CuO nanolubricant only showed light scuffing, while the SAE 40 sample showed severe exfoliation and scuffing. Wear rates had been enhanced by 33.5%. Overall, the 0.5% concentration of CNC-CuO nanoparticles improved the engine oil's thermophysical properties and performance. [ABSTRACT FROM AUTHOR]

Nanotechnology has emerged to be an essential aspect of science and technology. The growth of this field has been enormous specifically in the development of nanomaterials. Till date, numerous nanomaterials have been developed and designed to suit various applications from mechanical to biomedical. Among the developed nanomaterial, alumina (Al) has been subject of interest due to its notable chemical and physical properties. Specifically, in thermal properties, Al has been shown to have superior thermal conductivity, convective heat transfer coefficient and heat transfer coefficient properties. As such, Al has been utilized in different forms in various fields of applications and verified for its importance, significance and efficiency. Though it had shown outstanding results in the field engineering and sciences, their effect towards the environment and human health is yet to be explored extensively. The present paper aims to review the significance of Al nanoparticle addition in mono- and hybrid nanofluids. Also, this paper intends to provide the reader with an overview of the works that have been carried out using Al nanoparticles and their findings. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) is recognized as a viable and environmentally friendly energy source, utilized across various domains, from large-scale chemical energy exports to small-scale power generation in remote areas. However, the storage and distribution costs of H 2 present significant challenges. Ammonia (NH 3) emerges as a carbon-free hydrogen carrier, backed by a robust international transport and storage infrastructure. On-site hydrogen production can be efficiently achieved through NH 3 decomposition, predominantly via thermal catalysis. One innovative approach involves plasma technology, which utilizes NH 3 , alcohols, or hydrocarbons to produce pure hydrogen in plasma reactors. Nonthermal plasma (NTP) in particular, for NH 3 decomposition and H 2 production, has garnered considerable interest owing to its higher energy efficiency than thermal plasma systems. Furthermore, integrating NTP with catalysis, termed plasma-assisted catalysis, creates a synergistic effect, enhancing NH 3 decomposition efficiency for H 2 production through improved plasma-catalyst interactions. Consequently, NTP-catalysis holds the potential to revolutionize NH 3 conversion and utilisation in the future. To date, there have been limited studies on NTP-assisted catalytic NH 3 decomposition. This review article compiles the latest NTP-assisted catalytic NH 3 decomposition methodologies for H 2 production. It delves into the basics of plasma-assisted NH 3 decomposition, including adsorption, desorption, and the synergistic processes during plasma catalysis. Additionally, it examines the impact of NTP on the chemical states and properties of various catalysts and provides a comprehensive analysis of the factors influencing NH 3 -plasma decomposition. • Nonthermal plasma-assisted catalysis NH3 decomposition for COx-free H2 production. • Full NH 3 decomposition achieved at ambient temperature and pressure by applied NTP. • Combining plasma with catalysis has improved the NH3 efficiency decomposition. • NTP catalysis can potentially revolutionize NH3 conversion and utilisation in the future. [ABSTRACT FROM AUTHOR]

Among alternative fuels, hydrogen has significant promise as both a fuel and a carrier of energy. Hydrogen is projected to be a key alternative fuel in the near future to meet stringent pollution standards. Internal combustion (IC) engines, gas turbine, and aerospace industries use hydrogen as a fuel because it is non-toxic, odorless with high calorific value (CV), and combustible across a wide temperature range while also being a long-term renewable and less polluting energy source. The objective of this study is to investigate the impact of using different hydrogen rations on combustion behaver, engine performance, and emission characteristics in a dual fuel compressed ignition (CI) diesel engine. The tests were performed at speeds of 1500, 2000, and 2500 rpm at difference operating conditions. Hydrogen was introduced at flow rates of 21.4, 28.5, 36.2, 42.8, and 49.6 L per minute for each load. The findings reveal that hydrogen flow rate of 21.4 l/min and 42.8 l/min gives significant impact to engine coefficient of variation (COV) and the performance of the engine. In addition, the emissions level of CO, CO 2 and smoke were improved at the same flow rate. Moreover, the break thermal efficiency (BTE) has shown significant improvement at 21.4 l/min of hydrogen flow rate due to the reduction in combustion length and the movement of the combustion phasing toward the ideal phase. The use of hydrogen as alternative energy has important role as a future green energy source. • Hydrogen Usage as a Dual Fuel in a Compression Ignition Engine. • Hydrogen Mixing and Energy Consolidation for better Brake Specific Energy Consumption BSEC. • Enrichment of Hydrogen is Analyzed for Efficiency. [ABSTRACT FROM AUTHOR]

Abstract In past decades, nanofluid science has been widely investigated for thermal related activities. In thermal transport applications, thermal conductivity and dynamic viscosity are closely related to cooling system performance enhancement. The genuine anomaly behind thermal conductivity and dynamic viscosity enhancement in nanofluid is still undiscoverable. In this paper, comprehensive study on principle factor behind thermophysical property enhancement focusing on thermal conductivity and dynamic viscosity is conducted. Thus, a detailed review of existing experimental results for thermal conductivity and dynamic viscosity enhancement are compiled and discussed in this manuscript. Analytical tool approach such as fishbone diagram and summary tables are used to highlight principle factor for thermal conductivity and dynamic viscosity enhancement. The principal factor which influences the thermal conductivity is shape of the particle, nanofluid preparation, interfacial layer, Brownian motion, particle clustering and aggregation. Meanwhile, the principal factor influencing dynamic viscosity is the physical behavior of the particle, nanofluid preparation, particle clustering and aggregation. The optimum nanofluid should have high thermal conductivity and minimum viscosity. High thermal conductivity is mandatory for maximum heat absorption in thermal transport applications. Meanwhile, minimum viscosity ensures less pressure drop which reduces the power consumption and increases the overall efficiency of the system. [ABSTRACT FROM AUTHOR]

Green cooling system usage in machining is getting favors to minimize the environmental effect such as pollutions. Around 20% of the machining cost is about coolant usage in flooded cooling technique. Even though coolant has a reasonably low cost, their handling and disposing cost are very high and also, threatening toxic contents, disposal of used coolant is a big problem as it can lead to hazardous effect to the machining operates as well as to the environment. As an alternative, a cooling technique known as minimum quantity lubrication (MQL) was introduced in the machining operation. For MQL technique, the coolant should exhibit superior properties which are effective in machining operation when compared with the conventional machining coolant which is metal working fluid (MWF). Owing to the technology advancements by nanotechnology in nanomaterial, the nanofluid is a promising coolant that can replace the conventional machining coolant. In the present work, ethylene glycol/nanocellulose-based nanofluid is evaluated in terms of its thermo-physical properties and its effectiveness in machining performances which is temperature distribution in cutting tool and compare its effectiveness with MWF. Its effectiveness is tested in turning machining operation of SUS 304 stainless steel using cemented tungsten-cobalt (WC-Co)-coated carbide cutting insert. The turning operation by using ethylene glycol/nanocellulose-based nanofluid coolant with 0.5 vol% which exhibit a superior thermal conductivity of 0.449 W/m K than 0.267 W/m K thermal conductivity of MWF at 30 °C. The recorded lower amount of heat transfer to the cutting tool is 863 J compared with 1130 J when using MWF. On the other hand, the maximum temperature reading recorded at chip formed by using MWF is 225 °C whereas by using nanofluid is 154 °C which promises lower temperature distribution to chip formed during the machining operation. Also, the functionality of nanofluid as a thermal transport during machining is proven via chip formation observation analysis and scanning electron microscope (SEM) with energy-dispersive X-ray (EDX) spectrum analysis. [ABSTRACT FROM AUTHOR]

This paper investigates the properties of titanium alloy (Ti6Al4V) lattice structures fabricated via selective laser melting (SLM). Response surface method (RSM) was used to design the experiments. Four factors were selected to determine its influence on the Young’s modulus and compressive strength. Detailed characterizations such as dimensional accuracy, surface roughness, microstructure analysis, and compression test were conducted and reported. The built structures have a Young’s modulus ranging between 0.01 and 1.84 GPa. The statistical method was used to find the relationship between factors and Young’s modulus and compressive strength. Porosity was comprehended to play a significant role in determining the Young’s modulus and compressive strength. The error of the developed model was in the range of 0.5 to 1.3% compared with experimental results. Meanwhile, all the four factors found not to affect the surface roughness significantly. The statistical method recognizes the trends of the factor effect on the Young’s modulus, yield stress, and surface roughness. [ABSTRACT FROM AUTHOR]

The world natural gas reserve is plentiful. Instead of using gasoline to power ground vehicles, usage of Compressed Natural Gas (CNG) can improve the environment and reduce energy cost. However, most engines that runs on CNG are converted from gasoline based engine. Hence, the engines are not optimized for CNG. Other problems of converted engines are loss of power due to slower burn rate of CNG and gas displacement effect of CNG, hotter exhaust gas which degrade engine’s reliability, low mileage per tank and higher NO x . Since, converted engines are gasoline base engine, a dual fuel injection engine system can be developed to reduce the stated problems. Are activity controlled approach was incorporated where both gasoline and CNG are mixed before going into the combustion chamber. With this technique, when a blend of high reactive 35% gasoline and 65% CNG was used, the engine had its engine performance such torque, power and efficiency increasing by 10%. Also, the engine emissions such as hydrocarbon was reduced by 50% and carbon monoxide emission was reduced by 75% and NO x emission was reduced by 50% when compared with CNG baseline. Combustion of spark ignition engines converted to bi-fuel CNG is unstable and proper air and fuel mixing strategy is a concern here. [ABSTRACT FROM AUTHOR]

Currently, development of recycling, renewable, and sustainable products to replace fossil fuel products is an essential matter for industrial profiteering as well as environment protection. In the present study, waste cooking oil blended with SAE10W-40 should reduce the wear and friction on the piston skirt. Wear and friction performance were evaluated using piston skirt-liner contact tester, and the piston material was aluminum 6061. The design of experiment (DOE) was constructed using the response surface methodology (RSM) technique. Influence of different operating parameters such as rotational speeds (200 RPM, 250 RPM, 300 RPM), volume concentration (5% and 10% of waste oil), and loads (2 kg, 5.5 kg, and 9 kg) were optimized. Based on the results of moisture content and viscosity; as the concentration of waste cooking oil increases, the viscosity of the lubricant decreases. The lowest moisture content was at the 5% volume concentration. The increase in the coefficient of friction occurred in 5% and 10% volume concentration of waste cooking oil for both pairs. The RSM model showed that the speed, load, and volume composition have a significant effect on the coefficient of friction (COF) and specific wear rate (WR). The optimum obtained for both output (COF and WR) were 0.0596 μ for COF and 0.6827 μ for WR. The relevant parameters such as speed, load, and volume composition are 200 rev/min, 9.0 kg and 0.7071% of volume concentration respectively. Afield emission scanning electron microscope (FESEM) analysis shows mild abrasion, pitting corrosion, and severe delamination of the specimen surface increased when running at higher load. [ABSTRACT FROM AUTHOR]

Modern nanotechnology can produce metallic or non-metallic particles of nanometer dimensions that have unique optical, mechanical, magnetic, electrical, and thermal properties. The purpose of this review is to summarise important published articles on the enhancement of convection heat transfer using nanoparticles dispersed in Ethylene Glycol (EG) and the effects on thermal properties and applications. This paper reviews all the articles relevant to nanoparticles suspended in EG. The studies of thermal properties including experimental measurement and correlations are reported. The effects of nanofluid volume fraction, temperature, and base fluid have been included. The stability of nanofluid was shown through testing to avoid agglomeration and clusters for many applications. In this paper, the applications of nanofluids in different types of heat exchangers, cooling systems, and solar energies are reviewed. In the field of economics, nanotech reduces manufacturing costs as a result of using a low-temperature process. In order to focus future studies of nanofluid applications, the articles on this field are summarized. [ABSTRACT FROM AUTHOR]

This paper discuss the tool life and wear mechanism in the end-milling of AISI304 stainless steel using a TiN-coated carbide insert with water-soluble coolant and nanoparticle-based coolant (TiO/EG). The cutting variables are cutting speed, feed rate, and axial depth. The end-milling operation using nanoparticle-based coolant (TiO/EG) obtains a high tool life compared with the end-milling operation using water-soluble coolant. In general, the tool failure when milling with water-soluble coolant was flank wear, cracking, chipping, and fracture at a cutting distance of 720 mm, but the milling process with nanoparticle-based coolant (TiO/EG) showed chipping and fracture at a cutting distance of 1200 mm. According to ISO 8688-2-1989 (E), the wear criterion for milling with water-soluble coolant is reached at an average cutting distance of 800 mm, but milling with nanoparticle-based coolant (TiO/EG) reached the ISO 8688-2-1989 (E) wear criterion at a cutting distance of 1300 mm. The SEM and EDX spectra show that there are nanolayers of Ti nanoparticles from the nanofluid embedded in and filling the holes in the insert, forming a layer which acts as a thermal bridge for the cutting insert. Attrition and oxidation at the cutting edge were the main tool wear mechanisms present during the end-milling operation with nanoparticle-based coolant (TiO/EG). An oxide layer formed during the oxidation wear which shielded the cutting tool from impact during the milling process. [ABSTRACT FROM AUTHOR]

This article comprehensively investigates single (GNP) and hybrid nanofluids (GNPs/CNC nanoparticles), including nanofluid preparation and thermophysical properties. Nanoparticles were characterized using field emission scanning electron microscope, transmission electron microscope and X-ray diffraction analysis. A two-step approach is used in nanofluid preparation, and various analytical practices determine the prepared nanofluids. The range of the temperature set to measure the thermal conductivity of nanofluids is 20 °C to 50 °C using the ASTM D2717–95 norm. The present study range of the nanofluid volume concentration is from 0.01 vol% to 0.2 vol%. For the single GNP nanofluid, temperatures at room level indicated the thermal conductivity value in the range of 0.366 W·m−1·K−1 to 0.441 W·m−1·K−1; for hybrid nanofluid, the thermal conductivity values are 0.501 W·m−1·K−1 to 0.551 W·m−1·K−1. In addition, nanofluid's viscosity, density and specific heat capacity are the experimental density value increased with the concentration of nanoparticles with 1050 kg/m3 and 1060 kg/m3 for 0.01 % concentration of single/hybrid nanofluids, respectively. Finally, based on the findings, it can be determined that the thermal properties of the selected nanoparticles are beneficial, and hybrid nanofluid is an acceptable alternative to conventional/water-based fluids in terms of thermal properties in operational systems. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) highlights developing complex and efficient parts for various uses. Fused deposition modelling (FDM) is the most frequent fabrication procedure used to make polymer products. Although it is widely used, due to its low characteristics, such as weak mechanical properties and poor surface, the types of polymer material that may be produced are limited, affecting the structural applications of FDM. Therefore, the FDM process utilises the polymer composition to produce a better physical product. The review's objective is to systematically document all critical information on FDMed-polymer composite processing, specifically for part fabrication. The review covers the published works on the FDMed-polymer composite from 2011 to 2021 based on our systematic literature review of more than 150 high-impact related research articles. The base and filler material used, and the process parameters including layer height, nozzle temperature, bed temperature, and screw type are also discussed in this review. FDM is utilised in various biomedical, automotive, and other manufacturing industries. This study is expected to be one of the essential pit-stops for future related works in the FDMed-polymeric composite study. [ABSTRACT FROM AUTHOR]

This paper is concerned with the optimization of the surface roughness when milling aluminium alloys (AA6061-T6) with carbide coated inserts. Optimization of milling is very useful to reduce cost and time for machining mould. Potential support vector machine (PSVM) is used to develop surface roughness predicted model. Design of experiments method and response surface methodology techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through analysis of variance. The experiments results are compared with predictive model developed by PSVM. The optimum machining conditions in favor of surface roughness are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about 2-9 %) when compared to experimental results. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the wear mechanism and tool life when machining Hastelloy C-22HS with coated carbide. The experiment was conducted using four different cutting tool materials under wet condition – namely, Physical Vapor Deposition (PVD) coated with TiAlN; TiN/TiCN/TiN; Chemical Vapor Deposition (CVD) coated with TiN/TiCN/Al2O3; and TiN/TiCN/TiN – to study the tool behavior, in terms of wear and tool life machining of Hastelloy C-22HS. Tool failure modes and wear mechanism were examined at various cutting parameters. Flank wear, chipping, notching, plastic lowering at cutting edge, catastrophic and wear at nose were found to be the predominant tool failure for the four types of cutting tools, especially with CVD tools. Attrition/adhesion, oxidation and built-up edge (BUE) are the wear mechanisms observed in all cutting tools. The results obtained indicated that PVD cutting tools performed better than CVD cutting tools, in terms of tool life with current parameters. [ABSTRACT FROM AUTHOR]

Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness. [ABSTRACT FROM AUTHOR]

Abstract: Based on the Response Surface Methodology (RSM), the development of first- and second-order models for predicting the Air Diffusion Performance Index (ADPI) in a displacement-ventilated office is presented. By adopting the technique of Computational Fluid Dynamics (CFD), the new ADPI models developed are used to investigate the effect of simultaneous variation of three design variables in a displacement ventilation case, i.e. location of the displacement diffuser (L dd), supply temperature (T) and exhaust position (L ex) on the comfort parameter ADPI. The RSM analyses are carried out with the aid of a statistical software package MINITAB. In the current study, the separate effect of individual design variable as well as the second-order interactions between these variables, are investigated. Based on the variance analyses of both the first- and second-order RSM models, the most influential design variable is the supply temperature. In addition, it is found that the interactions of supply temperature with other design variables are insignificant, as deduced from the second-order RSM model. The optimised ADPI value is subsequently obtained from the model equations. [Copyright &y& Elsevier]

The Finite Element Method and Response Surface Method are used to find the effect of milling parameters (Cutting speed, Feedrate and Axial depth) on plastic strain when milling Hastelloy C-22HS. This simulation gain more understanding of the strain distribution in metal cutting. Response surface method (RSM) has been used to minimize the number of simulation. The contour plot from the RSM shows the relationship between variables (cutting speed, feedrate and axial depth) and response (plastic strain - rate). The friction interaction along the tool-chip interface is modeled with Coulomb friction law. [ABSTRACT FROM AUTHOR]

Abstract: The present paper discusses the development of the first and second order models for predicting the cutting force produced in end-milling operation of modified AISI P20 tool steel. The first and second order cutting force equations are developed using the response surface methodology (RSM) to study the effect of four input cutting parameters (cutting speed, feed rate, radial depth and axial depth of cut) on cutting force. The cutting force contours with respect to input parameters are presented and the predictive models analyses are performed with the aid of the statistical software package Minitab. The separate affect of individual input factors and the interaction between these factors are also investigated in this study. The received second order equation shows, based on the variance analysis, that the most influential input parameter was the feed rate followed by axial depth, and radial depth of cut and, finally, by the cutting speed. It was found that the interaction of feed with axial depth was extremely strong. In addition, the interactions of feed with radial depth; and feed rate with radial depth of cut were observed to be quite significant. The predictive models in this study are believed to produce values of the longitudinal component of the cutting force close to those readings recorded experimentally with a 95% confident interval. [Copyright &y& Elsevier]

Hydrogen energy possesses immense potential in developing a green renewable energy system. However, a significant problem still exists in improving the photocatalytic H 2 production activity of metal-free graphitic carbon nitride (g-C 3 N 4) based photocatalysts. Here is a novel Cu 3 P/CdS/g-C 3 N 4 ternary nanocomposite for increasing photocatalytic H 2 evolution activity. In this study, systematic characterizations have been carried out using techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Raman spectra, UV–Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area analysis (BET), electrochemical impedance (EIS), and transient photocurrent response measurements. Surprisingly, the improved 3CP/Cd-6.25CN photocatalyst displays a high H 2 evolution rate of 125721 μmol h−1 g−1. The value obtained exceeds pristine g-C 3 N 4 and Cu 3 P/CdS by 339.8 and 7.6 times, respectively. This could be the maximum rate of hydrogen generation for a g–C 3 N 4 –based ternary nanocomposite ever seen when exposed to whole solar spectrum and visible light (λ > 420 nm). This research provides fresh perspectives on the rational manufacture of metal-free g-C 3 N 4 based photocatalysts that will increase the conversion of solar energy. By reusing the used 3CP/Cd/g-C 3 N 4 photocatalyst in five consecutive runs, the stability of the catalyst was investigated, and their individual activity in the H 2 production activity was assessed. To comprehend the reaction mechanisms and emphasise the value of synergy between the three components, several comparison systems are built. Sphere-like Cu 3 P/CdS/g-C 3 N 4 photocatalyst was developed using hydrothermal route followed by ball milling and wet impregnation assisted method. A highest hydrogen production of 125721 μmol h−1g−1 was obtained for the above nanocomposite containing 6.25 wt% of g-C 3 N 4. [Display omitted] • Sphere-like Cu 3 P/CdS/g-C 3 N 4 composites was developed for visible light activity. • Metal free composites for H 2 evolution under visible light illumination was achieved. • The improved charge separation, transfer and transport results highest H 2 production. • Best activity results are observed for 3CP/Cd-6.25CN catalysts supported on g-C 3 N 4. • First time we report highest H 2 production activity for Cu 3 P/CdS/g-C 3 N 4 composites. [ABSTRACT FROM AUTHOR]

In the pursue of a carbon-free economy, the utilization of fuels with low or zero carbon footprint account for only 1% of global final energy demand, a share that is predicted to follow a dramatic growth to 20% by 2050. Ammonia (NH 3) has become dominant in the international transportation and storage of low-carbon alternative fuels. NH 3 is regarded as an alternative fuel, as a carbon-free fuel, and renewable hydrogen (H 2) carrier with high energy density, and its production and distribution infrastructure are well established. However, a current challenge is that NH 3 has a lower burning velocity and a narrow flammability limit. Thus, the use of NH 3 has numerous limitations in practical combustion applications. Blending NH 3 with H 2 is considered a solution that has been proposed to enhance NH 3 combustion by improving ignition, flammability, and H 2 safety issue. Using NH 3 blended with H 2 as a fuel in combustion systems is a practical approach to decarbonizing the energy sector. Thus, this review highlights the existing influential studies and ongoing research on NH 3 /H 2 blended fuels. The review covers NH 3 assists the safety behaviour of H 2 use, in-situ NH 3 dissociation, NH 3 and H 2 properties, NH 3 /H 2 combustion characterization, techniques for low NO x NH 3 /H 2 combustion, and challenges for NH 3 /H 2 combustion. Finally, recommendations for future studies are provided for further developing the utilization of NH 3 /H 2 as blended fuel. • Ammonia/hydrogen blends as carbon-free fuels have been reviewed. • H 2 is an ideal promoter for improving NH 3 combustion. • Effects of NO x formation and Low- NO x strategies are discussed. • Combining two-stage combustion and humidified operation could achieve greater NO reduction. • Challenges of NH 3 /H 2 combustion have been discussed. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) are increasingly gaining prominence in thermal energy storage due to their impressive energy storage capacity per unit volume, especially in applications with low and medium temperatures. Nevertheless, PCMs have significant limitations regarding their ability to conduct and store heat, primarily due to their inadequate thermal conductivity. One potential solution for improving the thermal conductivity of PCMs involves the inclusion of nanoparticles into them. However, a recurring issue arises after several thermal cycles, as most nanoparticles have a tendency to clump together and settle at the container's base due to their low interfacial strength and poor compatibility. To address this challenge, including surfactants such as sodium dodecylbenzene sulfonate (SDBS) has emerged as a prevalent and economically viable approach, demonstrating a substantial impact on the dispersion of carbon nanoparticles within PCMs. The foremost objective is to investigate the improvement of thermal energy storage by utilizing graphene nanoplatelets (GNP), which are dispersed in A70 PCM at various weight percentages (0.1, 0.3, 0.5, 0.7, and 1.0), both with and without the use of surfactants. The findings indicate a remarkable enhancement in thermal conductivity when GNP with surfactants is added to the PCM, showing an impressive increase of 122.26% with a loading of 1.0 wt.% compared to conventional PCM. However, when 1.0 wt.% pure GNP was added, the thermal conductivity only increased by 48.83%. Additionally, the optical transmittance of the composite containing ASG-1.0 was significantly reduced by 84.95% compared to conventional PCM. Furthermore, this newly developed nanocomposite exhibits excellent stability, enduring 1000 thermal cycles and demonstrating superior thermal and chemical stability up to 257.51 °C. Due to its high thermal stability, the composite NePCM is an ideal candidate for preheating in industrial and photovoltaic thermal (PVT) applications, where it can effectively store thermal energy. [ABSTRACT FROM AUTHOR]

Solar energy is the most plentiful renewable energy source that has the capability to keep up with the growing demand. When the sun's energy is not available, thermal energy storage (TES) using phase change material (PCM) is a promising technique for storage and utilization. However, PCM's low thermal conductivity may limit its use. The use of nanomaterials to enhance the thermal conductivity is one of the prominent solutions to overcome this issue. This research work reports that graphene nanoparticles (0.1%, 0.3%, 0.5%, 0.7% and 1% mass) enhanced paraffin wax (PW) to improve the thermophysical properties and transmittance capability. Thermogravimetric analyzer (TGA), differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR) and ultra-violet visible spectroscope (UV–VIS) were used for the characterization of the base PCM and nano-enhanced phase change materials (NePCM) composites. A significant improvement of 110% in thermal conductivity was obtained at 0.7% mass ratio compared to base PW without compromising the prepared composites' latent heat storage (LHS) capacity. TGA and FTIR outcomes demonstrated excellent thermal and chemical stability, respectively. To check the thermal reliability of composite, the PW and nanocomposite were subjected to repeated thermal cycling. The outcome evidence that the NePCM composite had consistent thermal energy storage properties even after repeated thermal cycles. The composite's light transmission was drastically lowered by 56.34% (PW/Gr-0.5) compared to base PW, resulting in PW/Gr composite has better thermal reliability in relation to thermal conductivity and LHS than base PCM, which can be used specifically in photovoltaic thermal systems and TES. [ABSTRACT FROM AUTHOR]

This study aims to determine the optimum geometrical and operating parameters of supercritical carbon dioxide (ScCO2) flow through a straight pipe for enhanced heat transferusing the Response Surface Method (RSM). Inlet pressure, inlet temperature, mass flow rate, and pipe inner diameter are selected as design variables while Nusselt number (Nu) and pressure drop are chosen as response functions. The ranges of the input variables considered in the study are inlet pressures (7–10 MPa), inlet temperature (35–80 °C), mass flowrate (0.02–0.05 kg/s), and tube inner diameter (2.8–4.5 mm). The accuracy and validity of the developed mathematical models are validated by comparing the simulation results with published experimental values. The sensitivity analysis results of Nu indicated that the best heat transfer in ScCO2 cooling is found to be associated with the lowest inlet pressure and temperature, the lowest tube diameter, and the highest mass flow rate. Moreover, the best flow conditions with minimum pressure drop are associated with the highest and lowest inlet pressure and temperature, respectively, as well as the highest tube diameter and lowest mass flow rate. These parameter combinations could help reduce the pumping power associated with a high pressure drop. [ABSTRACT FROM AUTHOR]

Highlights • Experimental Study on Nano Lubricant Containing Cellulose Nanocrystal (CNC). • Enhanced tribological performance was measured using piston–skirt liner tribometer,SEM and EDX. • 0.1% CNC demonstrates excellent tribological properties including the lowest COF and the strongest wear resistance. Abstract A novel Cellulose Nanocrystals (CNC) nanoparticles were proposed as green additive as green additives for improving tribological properties of lubricants. Enhanced tribological performance was measured using piston–skirt liner tribometer under variable load, speed and temperature; and varying concentrations of nanoparticles in lubricating oil. Study on a worn surface on the plate was characterized by SEM and EDX. This study shows that the mixing of CNC nanoparticles in engine oil significantly reduces the friction and wear rate and hence improves the lubricating properties of engine oil. Base oil containing 0.1% CNC demonstrates excellent tribological properties including the lowest COF and the strongest wear resistance under all lubrication conditions. An elemental content in EDX analysis reveals that Carbon and Aluminum were the most elements present. [ABSTRACT FROM AUTHOR]

Highlights • Experimental Study on Nano Lubricant Containing Cellulose Nanocrystal (CNC). • CNC nanoparticles were suspended at five different volume concentrations in the engine oil. • 1% CNC nanoparticle with base 0il SAE40 lubricant shows the highest value of viscosity index. Abstract Nano-lubricant is a new kind of engineering lubricant composed of nanometer-sized particle dispersed in a base lubricant. Recently, nanoparticles have been explored as lubricant additives for improving the stability and lubricity properties of a technological fluid. Cellulose nanocrystals (CNC), a unique and natural material extracted from native cellulose, has gained much attention in many field application due to its remarkable physical properties, special surface chemistry, and excellent biological properties, making them attractive as a green lubricant additive. The purpose of this study is to investigate the characterization of the CNC nanoparticles and to evaluate the influence of CNC nanoparticles on the lubricating properties added to the base oil. In this study, CNC nanoparticles were prepared and suspended in five different volume concentrations in the engine oil (0.1, 0.3, 0.5, 0.7 and 0.9%). The kinematic viscosity and viscosity index of the resulting nano lubricant was determined while varying both the nanoparticle volume fraction and the temperature. The size, morphology, and structure of CNC nanoparticles were characterized using Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray (EDX) and X-ray diffractions (XRD). The dispersion analysis of CNC nanoparticles in lubricating oil using UV spectrometer confirms that CNC nanoparticles possess good stability and solubility in the lubricant and improve the lubricating properties of the engine oil. The overall results of this experiment reveal that the addition of CNC nanoparticle with base 0il SAE40 lubricant shows the highest value of VI and most suitable concentration for improving properties of the base oil. [ABSTRACT FROM AUTHOR]

The emphasis of this paper is to evaluate the thermophysical properties of crystalline nanocellulose (CNC)-based nanofluid and the optimized machining parameters (cutting speed, feed rate and depth of cut) for machining using CNC-based nanofluid. Cutting tool temperature and formed chip temperature during machining are determined with CNC-based coolant and metal working fluid. Minimum quantity lubrication technique is used to minimize the usage of the coolant. Nanocellulose coolant with a concentration of 0.5% shows better thermal conductivity and viscosity. Total heat produced at the cutting tool and the temperature generated at the chip during machining shows significant improvement using CNC-based nanofluid. Statistical analysis reveals that feed rate and depth of cut contribute around 27.48% and 22.66% toward cutting temperature. Meanwhile, none of the parameters significantly affects the heat transfer. The multi-objective optimization reveals that the optimum parameter for machining using CNC-based nanocoolant is: cutting speed = 120, feed rate = 0.05 and depth of cut = 1.78 which produces heat transfer of 379.44 J and cutting temperature of 104.41 °C. [ABSTRACT FROM AUTHOR]

Highlights • Machining performances using ethylene glycol/nanocellulose based nanofluid. • 0.5 vol% EG/nanocellulose based MWF generates 1130 J of heat transfer at 30 °C. • Maximum temperature at chip formed by using nanofluid is 154 °C. Abstract In this paper, cellulose nanocrystal (CNC) – ethylene glycol (EG) + Water (W) based nanofluid was developed and assessed for their thermophysical properties and the usefulness towards machining performances. The nanofluid was prepared by adopting two-step preparation method and at volume concentration of 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.1%, 1.3% and 1.5%. The nanofluid with 1.3% and 1.5% concentration showed to have superior the conductivity properties, around 0.559 W/m·K at 70 °C. However, the 0.5% concentration has the highest stability with 0.52 W/m·K at 70 °C. The 0.5% nanofluid concentration was then selected for the machining performance evaluation. The machining performance was evaluated by using a lathe machining operation to determine the heat transfer and tool life properties. The cutting variables such as cutting speed, depth of cut and feed rate are varied to understand the effect of developed nanofluid on the machining bahaviour. Findings revealed that the tool failure on machining using MWF is flank wear, chipping and abrasion and fractured at the maximum cutting distance of 500 mm. However, machining using CNC-EG+W nanofluid revealed the tool failure to be flank wear, adhesion and build- up-edge (BUE) and fractured at the maximum cutting distance of 772 mm. [ABSTRACT FROM AUTHOR]

The main objective of this study is to determine the optimal blend ratio of fusel oil–gasoline before and after water extraction (FBWE10, FBWE20, FAWE10, and FAWE20) regarding the performance and emissions of spark ignition engine using response surface methodology (RSM). The multi-objective optimization is applied to maximize the brake power, brake thermal efficiency and minimize the brake specific fuel consumption (BSFC), NOx emission, HC emission and CO emission. The water content of fusel oil has been extracted by employing rotary extractor method. The experimental of this study has been carried out with different fusel oil–gasoline blends, different throttle valve opening position (15%, 30%, 45% and 60%) and different engine speed (1500, 2500, 3500 and 4500 rpm). All the developed models for responses were determined to be statistically significant at 95% confidence level. The study results reveal an improvement in heating value of fusel oil after water extraction with FAWE20 (80 vol% gasoline fuel, 20 vol% fusel oil after water extracted) as the optimally blended fuel. The best condition of engine parameters with FAWE20 were 55.4% of WOT for load and 4499 rpm engine speed. In additional of the optimal values with a high desirability of 0.707 were 62.511 kW, 241.139 g/kW h, 36%, 1895.913 ppm140.829 ppm and % for brake power, BSFC, BTE, NO x , HC and CO emissions respectively. The reduction of water content in fusel oil has a statistical significance influence to increases BTE, NO x emission and decreases the BSFC, HC and CO emissions. [ABSTRACT FROM AUTHOR]

• The engine oil needs to enhance its properties to reduce the wear on the piston. • The addition of CNC-CuO nanoparticles in the engine improved thermophysical properties behaviour's performance at 0.5% concentration. • The results can be beneficial for the heat transfer application, especially for tribological. The primary objective of the present analysis is to investigate the thermophysical properties of hybrid nanocellulose and copper (II) oxide nanoparticles added to engine oil as a lubricant for piston ring-cylinder liner application. Kinematic viscosity, viscosity index (VI) and dynamic viscosity have been performed for measurement of properties at varying temperatures (ranging from 30 °C to 90 °C) and different concentrations (ranging from 0.1 % to 0.9 % volume concentration). Thermal characteristics have been measured using similar temperatures and concentrations to determine thermal conductivity and specific heat capacity. In the results, as the concentration of the CNC-CuO nanoparticle increases, the VI also increases. This proves the combination of CNC-CuO particles with engine oil improves the lubricity of the base oil concerning its viscosity by 44.3 %-47.12 %. The lowest and highest improvements in the dynamic viscosity were 1.34 % and 74.81 %. The highest increment of thermal conductivity ratio for the selected nanolubricant was 1.80566 % in the solid concentration of 0.1 % at 90 °C. The specific heat capacity of nanolubricant tends to reduce slightly with an increase in temperature. Overall, the addition of CNC-CuO nanoparticle in the engine improved thermophysical properties behaviour's performance at 0.5 % concentration. The results can benefit the heat transfer application, especially tribological. [ABSTRACT FROM AUTHOR]

A radiator is used to remove a portion of the heat generated by a vehicle engine. It is challenging to efficiently maintain the heat transfer in an automotive cooling system even though both internal and external systems need enough time to keep pace with catching up with evolving engine technology advancements. The effectiveness of a unique hybrid's heat transfer nanofluid was investigated in this study. The hybrid nanofluid was mainly composed of graphene nanoplatelets (GnP), and cellulose nanocrystals (CNC) nanoparticles suspended in a 40:60 ratio of distilled water and ethylene glycol. A counterflow radiator equipped with a test rig setup was used to evaluate the hybrid nano fluid's thermal performance. According to the findings, the proposed GNP/CNC hybrid nanofluid performs better in relation to improving the efficiency of heat transfer of a vehicle radiator. The suggested hybrid nanofluid enhanced convective heat transfer coefficient by 51.91%, overall heat transfer coefficient by 46.72%, and pressure drop by 34.06% with respect to distilled water base fluid. Additionally, the radiator could reach a better CHTC with 0.01% hybrid nanofluid in the optimized radiator tube by the size reduction assessment using computational fluid analysis. In addition to downsizing the radiator tube and increasing cooling capacity over typical coolants, the radiator takes up less space and helps to lower the weight of a vehicle engine. As a result, the suggested unique hybrid graphene nanoplatelets/cellulose nanocrystal-based nanofluids perform better in heat transfer enhancement in automobiles. [ABSTRACT FROM AUTHOR]

The effects of cutting parameters on the wear mechanisms in the end milling of aluminium alloy AA6061 with minimum quantity lubrication (MQL) conditions using water-based TiO 2 nanofluid were investigated. Three different cutting speeds of 5200, 5400 and 5600 rpm were used. The MQL flow rates used were 0.65 ml/min and 1.0 ml/min, while the TiO 2 nanoparticles used were of different volume fractions in the aqueous solutions of 0.5, 2.5 and 4.5%. The results showed that the adhesion of the work material is the major tool damage phenomenon. In addition, abrasion was observed. The major benefit from the water-based nanofluid MQL was shown in the edge integrity i.e., edge chipping and edge fracture were seen in very few cases especially with a higher depth of cut higher. This is attributed to the cooling effect produced by the latent heat of vaporization of the water resulting in the lowering of temperature in the cutting zone. The volume fraction of 2.5% TiO 2 nanoparticles appeared more feasible in terms of tool damage. The effectiveness of the non-conventional nanofluid MQL was also discussed. A non-deterministic component of the sustainability index, for the milling process with the MQL, was calculated using fuzzy logic. The basic objective is to quantify the non-deterministic component of the sustainability index by using the fuzzy rule-based model for the performance analysis of machining with MQL. The results show the prospective utilization of water-based TiO 2 nanofluid as the MQL medium. Thus, it is beneficial for the higher cooling rates of water integrated with the lubrication characteristics of nanoparticles. [ABSTRACT FROM AUTHOR]

The combustion of spark ignition engines converted to bi-fuel CNG is unstable and proper air and fuel mixing strategy is a concern. Also, CNG fuel causes the coefficient of variation for indicated mean effective pressure (COV imep ) higher than 10% which is into the region of unstable combustion. In order to create stable combustion more turbulence is required. This paper studies the valve movement with dissimilar valve lift (DVL) to increase swirl in the engine. The intake valve is the last point of airflow entry into an engine and the modification of the movement can contribute to increase turbulence. Three DVL setting simulated via computational fluid dynamics (CFD) gave improvement in peak pressure by 4% and a 32.2% improvement in flame propagation speed compared to baseline CNG. Engine testing shows that, the engine COV imep improves up to 8.7%, while efficiency improves by 5.7% and BSFC is reduced by 5.4% respectively with the 1 mm DVL at 4000 rpm compared to baseline CNG. The rate of heat release (ROHR) also shows early heat release of the fuel. The novelty is better mileage for future CNG engine design. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the optimal design parameters and to indicate which of the design parameters are statistically significant for obtaining a low coefficient of friction (COF) and low wear rate with waste palm oil blended with SAE 40. The tribology performance was evaluated using a piston-ring-liner contact tester. The design of experiment (DOE) was constructed by using response surface methodology (RSM) to minimize the number of experimental conditions and to develop a mathematical model between the key process parameters such as rotational speeds (200 rpm to 300 rpm), volume concentration (0% to 10% waste oil), and applied loads (2 kg to 9 kg). Analysis of variance (ANOVA) test was also carried out to check the adequacy of the empirical models developed. Scanning electron microscopy (SEM) was used to examine the damage features at the worn surface under lubricant contact conditions. [ABSTRACT FROM AUTHOR]

• The new BTMS has two heat transfer paths, including OHP and liquid cooling plate. • Pulsating flow improves OHP stability through periodic enhanced thermal loads. • Optimal OHP stability lies in 38% or 62% duty cycles, 0.03–0.05 Hz frequencies. • Stably operating OHP enhances the new system's heat transfer performance. After a comprehensive review of oscillating heat pipe (OHP) based on battery thermal management system (BTMS), a novel battery liquid-cooling system with a ⊥-shaped OHP is presented to increase the volume utilization efficiency of battery module and the total amount of heat dissipation. The new system retains the heat transfer path of the OHP while incorporating an additional heat dissipation route where the liquid cooling plate is in direct contact with the cells. In this paper, pulsating flow is used to tackle the problem of the OHP failing to operate stably due to the insufficient heat load achieved in the new system. The parametric effects of pulsating flow frequencies, cooling initiation temperatures, and duty cycles on the operational performance of the OHP and the average surface temperature of the battery module ( T b ) within the new system were investigated. The results indicate that pulsating flow periodically elevates the heat load on the battery surface, enhancing the OHP working properly. The smaller the pulsating flow frequency, the greater the impact on the temperature fluctuations of the new system. The T b is lowest when the pulsating flow frequencies range from 0.03 Hz to 0.05 Hz. Beyond a frequency of 0.06 Hz, the OHP cannot operate stably. Additionally, moderately increasing the cooling initiation temperature is beneficial for enhancing the average temperature oscillation amplitude of the OHP. The cooling initiation temperature between 45 °C and 47 °C results in a better T b . Both pulsating flow duty cycles of 38% and 62% contribute to OHP running effectively. The new system with OHP under optimum pulsating flow condition has the optimal T b , eventually rising by 17.5 °C, which is a 9.8% decrease in temperature rise compared to the system without OHP. And the battery module's surface temperature uniformity has been improved through a reduction of 1.3 °C in the maximum temperature difference ( ΔT max ), amounting to a 17.8% decrease. It has been proved that the improved thermal performance of the new system under pulsating flow is attributed to the stable operation of the OHP. [ABSTRACT FROM AUTHOR]

Recent decades have witnessed a surge in research interest in bio-nanocomposite-based packaging materials, but still, a lack of systematic analysis exists in this domain. Bio-based packaging materials pose a sustainable alternative to petroleum-based packaging materials. The current work employs bibliometric analysis to deliver a comprehensive outline on the role of bio nanocomposites in packaging. India, Iran, and China were revealed to be the top three nations actively engaged in this domain in total publications. Islamic Azad University in Iran and Universiti Putra Malaysia in Malaysia are among the world's best institutions in active research and publications in this field. The extensive collaboration between nations and institutions highlights the significance of a holistic approach towards bio-nanocomposite. The National Natural Science Foundation of China is the leading funding body in this field of research. Among authors, Jong whan Rhim secured the topmost citations (2234) in this domain (13 publications). Among journals, Carbohydrate Polymers secured the maximum citation count (4629) from 36 articles; the initial one was published in 2011. Bio nanocomposite is the most frequently used keyword. Researchers and policymakers focussing on sustainable packaging solutions will gain crucial insights on the current research status on packaging solutions using bio-nanocomposites from the conclusions. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM) is a non-conventional process for shaping hard metals and forming deep and complex-shaped holes by spark erosion in all kinds of electroconductive materials. The choice of the electrical parameters on the EDM process depends impressively on workpiece-electrode material combination. In this research, an effort has been made to study the surface finish characteristics of the machined surface in EDM on Ti-5Al-2.5Sn titanium alloy. The microstructure of the machined surface is investigated for discharge energy and electrode materials. The peak current, pulse-on time, pulse-off time, servo-voltage and electrode material (copper, copper-tungsten and graphite) are considered as process variables. The experimental work was performed based on an experiment design (central composite design). The surface roughness (SR) increases with peak current and pulse-on time and decreases with servo-voltage. Besides, the effect of the process parameters on surface roughness depends on electrode material. At low discharge energy, copper-tungsten electrode produces the finest surface structure whilst graphite delivers worst surface characteristics. Copper-tungsten with low discharge energy (low peak current and pulse-on time) can be used to obtain better surface finish. [ABSTRACT FROM AUTHOR]

The car radiator heat transfer enhancement by using TiO and SiO nanoparticles dispersed in water as a base fluid was studied experimentally. The test rig is setup as a car radiator with tubes and container. The range of Reynolds number and volume fraction are (250-1,750) and (1.0-2.5 %) respectively. Results showed that the heat transfer increases with increasing of nanofluid volume fraction. The experimental data is agreed with other investigator. [ABSTRACT FROM AUTHOR]

• Preparation of nanofluids using graphene nanoplatelets (GNP's) & cellulose nano crystal (CNC) in base fluid. • Development of stable homogeneous dispersion of GNP's & CNC/water-EG nanofluids. • GNPs and CNC hybrid nanofluid can be prepared with excellent dispersion stability. The heat transfer capacity of any thermal cooling system depends on two factors, i.e., the selection of the coolant and the geometrical pattern of the approach. This article summarizes nanofluids' preparation ranging from 0.01 % to 0.2 % using Graphene nanoplatelets & CNC dispersed in a base fluid. The combination of water with ethylene glycol (EG) is a form of customary heat transmit liquids regularly utilized in numerous energy practices to maintain the water's decent cooling (or heating) capability; thus, 60:40 ratio of EG: W mixture used as the base fluid for thermo-physical properties enhancements. These nanofluids prepared are not used with surfactants as it results in generating bubbles and contaminating the heat transfer channels, influencing the overall performance. XRD & FESEM techniques were used to analyze the surface. The investigated nanofluids remained stable, with no substantial sedimentation for 30 days. The results of GNPs/CNC nanofluids at 0.1% volume concentration has proper stability showing excellent colloidal stability in the base fluid of EG: W at a ratio of 60:40. The present hybrid nanofluid has the ability to switch the traditional heat transfer fluids leading to efficient & compact thermal structures. [ABSTRACT FROM AUTHOR]

Abstract: The increasing demand of nanofluids in industrial applications has led to increased attention from many researchers. In this paper, heat transfer enhancement using TiO2 and SiO2 nanopowders suspended in pure water is presented. The test setup includes a car radiator, and the effects on heat transfer enhancement under the operating conditions are analyzed under laminar flow conditions. The volume flow rate, inlet temperature and nanofluid volume concentration are in the range of 2–8 LPM, 60–80°C and 1–2% respectively. The results showed that the Nusselt number increased with volume flow rate and slightly increased with inlet temperature and nanofluid volume concentration. The regression equation for input (volume flow rate, inlet temperature and nanofluid volume concentration) and response (Nusselt number) was found. The results of the analysis indicated that significant input parameters to enhance heat transfer with car radiator. These experimental results were found to be in good agreement with other researchers' data, with a deviation of only approximately 4%. [Copyright &y& Elsevier]

Polyaniline nanotubes (PANI NTs) blended in refined, bleached and deodorized palm olein (RBDL) nanolubricants were prepared via a two-step method. Initially, the synthesized PANI NTs were characterized to investigate the morphology and elemental composition of the obtained PANI NTs. The obtained image from transmission electron microscopy clearly showed the presence of flake-like structure of PANI NTs. The presence of these PANI NTs was further affirmed with energy-dispersive X-ray analysis, which shows the presence of high carbon atoms (the main element for PANI NTs). The formulated surfactant-free nanolubricants were stabilized using ultrasonication with volume concentrations of 0.01, 0.03, 0.05, 0.1, 0.3 and 0.5%. The dispersion behavior of nanolubricants was investigated using visual sedimentation capturing, UV–Vis spectrophotometer and dynamic light scattering (DLS) method. The sedimentation observation of the nanolubricants over the duration of almost 1 month showed there was no sedimentation of the nanoparticles. UV–Vis spectra indicated that all the prepared PANI/RBDL nanolubricants followed Beer–Lambert law. The value of absorbance was found to be slightly decreased, with respect to the duration of time after sample preparation. The dispersion stability analysis supported by DLS method revealed that the amount of particles agglomeration increased after 1 month of preparation. The chemico-physical properties of prepared PANI/RBDL nanolubricants were further investigated by analyzing the chemical bonding using Fourier-transform infrared spectroscopy (FTIR). Additionally, this study intends to investigate the influence of PANI NTs toward the life cycle of base oil via thermogravimetric (TG) analysis. FTIR analysis showed that nanolubricants were chemically stable as there were only physical interactions between PANI additives and RBDL base oil, while the degradation behavior in TG curve demonstrated that the nanolubricants could withstand higher temperature as the volume concentration of nano-additives increased. Rheology and thermal conductivity properties of PANI/RBDL nanolubricants were performed by using rheometer and thermal properties analyzer, respectively. Viscosity measurement revealed that PANI/RBDL nanolubricants exhibited Newtonian behavior. Also, viscosity was found to have been increased with a volume concentration of PANI NTs but decreases with the increase in temperature. From the thermal conductivity measurement, it is proven that the PANI NTs dispersed in the RBDL palm base oil support the thermal properties enhancement. The 0.5% PANI/RBDL nanolubricants had achieved the highest thermal conductivity of 0.4301 W m−1 K −1 at 80 °C with enhancement percentage of 25.76% when compared to conventional base oil at a similar temperature. [ABSTRACT FROM AUTHOR]

The present work is focused on the Graphene-based nanofluids with high thermal conductivity which helps to improve the performance and enhance heat transfer. The thermal systems emphasis on the fluid coolant selection and statistical model. Graphene is a super-material, lighter than air, high thermal conductivity, and chemical stability. The purpose of the research is to work up with Graphene-based Nanofluids i.e., Graphene (G) and Graphene oxide (GO). Nanoparticles are dispersed in a base fluid with a 60:40 ratio Water & Ethylene Glycol and at different volume concentrations ranging from 0.01%-0.09%. Radiator model is designed in modelling software and louvered strip is inserted. The simulation (Finite Element Analysis) is performed to evaluate variation in temperature drop, enthalpy, entropy, heat transfer coefficient and total heat transfer rate of the considered nanofluids, results were compared by with and without louvered strip in the radiator for the temperature absorption. 58-60% enhancement of enthalpy observed when Graphene and Graphene oxide nanofluid was utilized. 1.8% enhancement of entropy is observed in 0.09% volume concentration of the Graphene and Graphene oxide nanofluid when louvered strips are inserted in the radiator tube at a flow rate of 3 LPM. With louvered strip inserted in the radiator, heat transfer coefficient enhanced by 236% for Graphene and 320% enhancement is identified for Graphene oxide nanofluid when compared to without louvered strip insert. The results stated that high performance is observed with the utilization of louvered strip in the radiator tube. [ABSTRACT FROM AUTHOR]