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Engine component endurance is related to fuel properties. Decreasing the sulfur content of a fuel reduces its lubricity, thus damaging engines and fuel systems. Therefore, promoting the use of a biofuel must involve assessing the functionality and lubricity of the fuel.

The ball-on-ring (BOR) wear tester was applied to determine the optimal additive concentration and the mechanism of reduction of the wear and friction of the diesel engine fuel injection system. The lubricating efficiency of the fuels was estimated by using a photomicroscope to measure the average diameter of the wear scar produced on the test ball. An optical microscope and scanning electronic microscope were used for wear surface examinations.

The wear test revealed that the wear diameter of the steel ball lubricated with either the pure petrodiesel or 20 Wt.per cent Jatropha curcas biodiesel blends was 1.36 or 1.05 mm, respectively. The experimental results indicated that when Jatropha curcas biodiesel was added into petrodiesels to reduce friction, the wear resistance of the fuel blends increased concurrently with increasing Jatropha curcas biodiesel concentration. This was attributed to the presence of stearic acid in Jatropha curcas biodiesel blends. Stearic acid has a strong affinity for metal surfaces; therefore, a chemical coating was formed between the two motion surfaces to protect the two contacted surfaces from wear. Therefore, the proposed Jatropha curcas biodiesel can be used to effectively enhance the lubricity of a petrodiesel under the condition of boundary lubrication.

Using biofuels as the fuels for diesel engines can assist developed and developing countries in reducing the impacts of their fossil fuel consumption on the environment.

This paper aims to evaluate the effect of biodiesel additive in fuel system of diesel engines to reduce wear characteristics. Biofuels are environmentally friendly and renewable alternatives to mineral-based fuels and cause low pollution; thus, they can be used to comply with future emission regulations to safeguard environmental and human health.

Two types of diesel fuel, pure petrodiesel and soybean oil, were compared for their fuel properties and tribological performance. The ball-on-disk wear testing method was used as an analytical tool for this purpose. The lubricating efficiency of the fuels was estimated using a photomicroscope to measure the average diameter of the wear scar produced on the test ball.

The wear experiments showed that the wear scar diameters were 1.13 and 0.94 mm for lubrication of the pure petro-diesel and soybean oil, respectively. However, fatty acids containing biodiesel typically have thicker molecular layers than mineral pure petro-diesel, and thus can reduce the wear rate of the sliding metals. This improved the boundary lubrication conditions and the lubricity of the fuel. Biodiesel fuels are effective lubricity enhancers and have greater lubricity enhancing properties than petro-diesel.

The ability of biodiesel to be highly biodegradable and its superior lubricating property when used in compression ignition engines make it an excellent fuel. Biofuel is an attractive alternative fuel to various energy sectors, particularly the transportation sector. Biofuel has immense potential for use in a sustainable energy mixture in the future.

The paper aims to investigate the optimal service quality and pricing for a mobile application (App) service supply chain (SSC) and analyze the impact of network externality on App SSC members' utilities. After that, the corresponding management inspirations and suggestions are put forward.

The paper developed a SSC consisted of an App service supplier and an App service operator. Our models aim to maximize the SSC members' utilities. By utilizing the game theory, equilibrium solutions are obtained. Numerical examples are used to manifest the impact of parameters on decisions by Matlab. Some management enlightenment could be obtained by comparison analysis.

Cooperating with an App service operator that asks for a lower revenue sharing ratio will enable the App service supplier to have sufficient funds to provide high-quality update service. With the increase of network externality, adopting a high-quality service strategy can bring higher utility to the App service operator and users. Pouring attention into consumer welfare moderately will improve the App service supplier's utility. Scenario CRS can achieve a win–win goal for App SSC members and consumers.

The innovations of this paper are as follows: Firstly, the authors investigate the optimal service quality and pricing for the App SSC, which has been discussed little in previous literature. Secondly, the authors discuss how network externality and enterprises' attention to consumer welfare affect the optimal decisions and utilities of App service supply chain members. Thirdly, this paper considers four different circumstances and determines the optimal operation scenario for App SSC through comparative analysis.

Energy is the prime mover of economic growth and is vital to the sustenance of a modern economy. Future economic growth depends heavily on the long-term availability of energy from sources that are affordable, accessible and environmentally friendly. Regulating the sulfur content in diesel fuel is expected to reduce the lubricity of these fuels, which may result in increased wear and damage of fuel injection systems in diesel engines.

The tribological properties of the biodiesels as additive in pure petro-diesel are studied by ball-on-ring wear tester to find optimal concentration, and the mechanism of the reduction of wear and friction will be investigated by optical microscopy.

Studies have shown that low concentrations of biodiesel blends are more effective as lubricants because of their superior polarity. Using biodiesel as a fuel additive in a pure petroleum diesel fuel improves engine performance and exhaust emissions. The high biodegradability and superior lubricating property of biodiesel when used in compression ignition engines renders it an excellent fuel.

This detailed experimental investigation confirms that biodiesel can substitute mineral diesel without any modification in the engine. The use of biofuels as diesel engine fuels can play a vital role in helping the developed and developing countries to reduce the environmental impact of fossil fuels.

To prolong engine life and reduce exhaust pollution caused by gasoline engines, the aim of this paper was to compare the lubrication properties of biofuel (ethanol) blends and pure unleaded gasoline.

Biofuels with a concentration of 0, 1, 2, 5 and 10 per cent were added to unleaded gasoline to form ethanol-blended fuels named E0, E1, E2, E5 and E10. Next, the ethanol-blended fuels and unleaded gasoline were used to power engines to facilitate comparisons between the pollution created from exhaust emissions.

Using ethanol as a fuel additive in pure unleaded gasoline improves engine performance and reduces exhaust emissions. Because bioethanol does not contain lead but contains low aromatic and high oxygen content, it induces more complete combustion compared with conventional unleaded gasoline.

Using biofuels as auxiliary fuel reduces environmental pollution, strengthens local agricultural economy, creates employment opportunities and reduces demand for fossil fuels.

The purpose of this paper is to evaluate the wear performance of carbon steel cladded with TiC powders by gas tungsten arc welding method. Because of poor wear resistance, carbon steels have limited industrial applications as tribological components.

The cladding microstructures were characterized by optical microscope, scanning electron microscope (SEM) and X-ray energy dispersive spectrometer. The wear behavior of the clad layer was studied with a block-on-ring tribometer.

The experimental results revealed that the metallurgical interface provided an excellent bond between the cladding and the carbon steel substrate. The cladding revealed no porosity or cracking, and particles were evenly distributed throughout the cladding layer. Hardness was increased from HRc 6.6 in the substrate to HRc 62 in the cladded layer due to the presence of the hard TiC phase.

The experiments confirm that the cladding surfaces of TiC particles reduce wear rate and friction. Increasing TiC contents also improves hardness and wear resistance at room temperature and under dry sliding wear conditions.

The purpose of this paper is to investigate the effects of abrasive contents, oxidizer contents, slurry flow rate and polishing time in achieving a mirror-like finish on polished surfaces. Chemical mechanical polishing (CMP) is now widely used in the aerospace industry for global planarization of large, high value-added components.

Optimal parameters are applied in experimental trials performed to investigate the effects of abrasive contents, oxidizer contents, slurry flow rate and polishing time in achieving a mirror-like finish on polished surfaces. Taguchi design experiments are performed to optimize the parameters of CMP performed in steel specimens.

Their optimization parameters were found out; the surface scratch, polishing fog and remaining particles were reduced; and the flatness of the steel substrate was guaranteed. The average roughness (Ra) of the surface was reduced to 6.7 nm under the following process parameters: abrasive content of 2 weight per cent, oxidizer content of 2 weight per cent, slurry flow rate of 100 ml/min and polishing time of 20 min.

To meet the final process requirements, the CMP process must provide a good planarity, precise selectivity and a defect-free surface. Surface planarization of components used to fabricate aerospace devices is achieved by CMP process, which enables global planarization by combining chemical and mechanical interactions.

Chemical mechanical polishing (CMP) has attracted much attention recently because of its importance as a nano-scale finishing process for high value-added large components that are used in the aerospace industry. The paper aims to discuss these issues.

The characteristics of aluminum nanoparticles slurry including oxidizer, oxidizer contents, abrasive contents, slurry flow rate, and polishing time on aluminum nanoparticles CMP performance, including material removal amount and surface morphology were studied.

Experimental results indicate that the CMP performance depends strongly on the oxidizer, oxidizer contents, and abrasive contents. Surface polished by slurries that contain nano-Al abrasives had a lower surface average roughness (Ra), lower topographical variations and less scratching. The material removal amount and the Ra were 124 and 7.61 nm with appropriate values of the process parameters of the oxidizer, oxidizer content, abrasive content, slurry flow rate and polishing time which were H₂O₂, 2 wt.%, 1 wt.%, 10 ml/min, 5 min, respectively.

Based on SEM determinations of the process parameters for the polishing of the surfaces, the CMP mechanism was deduced preliminarily.

Thick composite claddings of carbides on a metal matrix are ideal for use in components that are subject to severe abrasive wear. It is a metal matrix composite (MMC) that is reinforced by an appropriate ceramic phase and nano-diamond cladding to reduce friction and to protect the opposing surface. The paper aims to discuss these issues.

This work evaluated the wear performance of carbon steel cladded with TiC/nano-diamond powders by gas tungsten arc welding (GTAW) method. The microstructures, chemical compositions, and wear characteristics of cladded surfaces were analyzed by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX).

The cladding was uniform, continuous, and almost defect-free, and particles were evenly distributed throughout the cladding layer. The results of wear test indicate that the friction coefficient of the TiC+1.5% nano-diamond cladding is lower than that of AISI 1020 carbon steel. Thus, the wear scar area of the TiC+1.5% nano-diamond cladding is only one-tenth of the AISI 1020 carbon steel.

The experiments in this study confirm that, by reducing friction and anti-wear, the cladding layer prepared using the proposed methods can prolong machinery operating life.

The purpose of this work is to study tribological properties of liquid paraffin with SiO₂ nanoparticles as an additive, which are made by surface-modification method. Taguchi robust designs for optimization in synthesizing SiO₂ nanoparticles by sol-gel method.

The tribological properties of the SiO₂ nanoparticles as additive in liquid paraffin are studied by ball-on-ring wear tester to find out optimal concentration, and the mechanism of the reduction of wear and friction will be investigated by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and atomic force microscope (AFM).

Under optimal conditions identified by Taguchi robust designs method, SiO₂ nanoparticles with a narrow particle size distribution can be obtained and optimal concentrations of SiO₂ nanoparticles as additives in liquid paraffin have better properties than the pure paraffin oil.

It is shown in the paper that by reducing friction and AW, the lubricant prepared by the methods described can prolong operating hours of machinery.