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This paper investigates the influence of piston geometry design and spark plug position on the engine performance and emission characteristics at a range of speeds from 1200 rpm to 2200 rpm. Accordingly, the parameters of the indentation depth, the spark plug position, the location of the recess, and the engine's compression ratio are changed and evaluated. The concave center depth improved the mixture of air and fuel, increased power, and reduced fuel consumption. The power can be improved by up to 3% when the piston top recess is 25 mm. In addition, within a limited range, the combustion process and the engine's power and emission characteristics are enhanced when the engine's compression ratio rises. Increasing the depth of the depression on the top of the piston improves fluid flow in the cylinder, resulting in increased power, fuel efficiency, and emissions; however, the improvement between the indentations remains unclear. [ABSTRACT FROM AUTHOR]

In general, as compared to conventional combustion engines, the homogeneous charge compression ignition (HCCI) engine offers better fuel efficiency, NOx, and particulate matter emissions. The HCCI engine, on the other hand, is not connected to the spark plugs or the fuel injection system. This implies that the auto-ignition time and following combustion phase of the HCCI engine are not controlled directly. The HCCI engine will be confined to a short working range due to the cold start, high-pressure rate, combustion noise, and even knocking combustion. Biofuel innovation, such as ethanol-powered HCCI engines, has a lot of promise in today's car industry. As a result, efforts must be made to improve the distinctive characteristics of the engine by turning the engine settings to different ethanol mixtures. This study examines the aspects of ethanol-fueled HCCI engines utilizing homogenous charge preparation procedures. In addition, comparing HCCI engines to other advanced combustion engines revealed their increased importance and prospective consequences. Furthermore, the challenges of transitioning from conventional to HCCI engines are examined, along with potential answers for future upgrade approaches and control tactics. [ABSTRACT FROM AUTHOR]

Many worldwide scientists have concentrated on using waste heat recovery technology in automotive applications because of increasingly strict fuel consumption. The thermoelectric generator (TEG) has garnered significant interest in the automobile sector as a viable waste heat recovery solution over the past several decades. A short survey of thermoelectric materials and heat exchangers for TEG systems is initially presented in this paper. To overcome the heat exchanger's current shortcomings, some previous studies designed a variety of the heat exchanger geometry of the TEG system. They suggested concentric cylindrical TEG system utilizes an annular thermoelectric module instead of the traditional square-shaped one. It uses the heat pipe's benefits to improve radial heat transmission. A comparison of the water-inside and gas-inside arrangements indicated that the water-inside concentric cylindrical TEG system provided a greater power output in our simulations to test the performance of the proposed system. [ABSTRACT FROM AUTHOR]

In this study, oil was converted to biodiesel via transesterification reaction under the presence of CaO at the laboratory. This aims to evaluate and compare the influence of Jatropha oil with commercial diesel (CD) fuel on the engine operating characteristics. Secondly, this study is to compare engine performance and temperature characteristics of cooling water and lubricant oil under various engine operating conditions of the test engine fueled by Jatropha oil and CD. The results indicated that the engine torque of the engine running with Jatropha oil dropped from 0.2 kW to 0.3 kW at all speeds and its brake specific fuel consumption (BSFC) increased at almost every speed due to the low heating value and high viscosity of the Jatropha fuel. The BTEs of the engines fuelled with Jatropha oil was 0.3%, 1.0%, 0.6%, 0.7%, 1.1%, 1.6%, and 1.0% smaller than the BTEs of the engine when varied speed from 1000 rpm to 2200 rpm. However, the difference was trivial. Also, Jatropha oil contributed to reducing the oil temperature of lubricant and cooling water. [ABSTRACT FROM AUTHOR]

This study explored methods to evaluate the test engine characteristics operated based on the reactivity controlled compression ignition (RCCI) technology to reduce fuel consumption and exhaust emissions, especially PM and NOx. Consequently, gasoline and diesel, respectively, considered as the low reactivity fuel (LRF) and high reactivity fuel (HRF), are injected in the intake manifold and combustion chamber. The experimental procedure is conducted at a constant speed of 2000 rpm, and brake mean effective pressure (BMEP) from low load 0.84 bar to high load 4.24 bar. The injection strategy is varied according to the engine loads. Indeed, at the low and medium engine load condition, the diesel fuel is injected double injection pulse, at the high load, the diesel fuel is injected single injection pulse. The injection timing is advanced from the top dead center (TDC) until knocking happens or the coefficient of variation (COV) higher than 10%, and maximum advanced injection timing is 65 crank angle degree (°CA) before the top dead center (BTDC). The results of advanced injection timing show that limit of advanced timing in low load is COV while at high load is knocking; at medium load, the diesel injection timing can be advanced to 65°CA BTDC. The exhaust emissions of CO and HC are higher than conventional diesel engines, while soot is hugely lower in all operating points. NOx emission is much dependent on injection timing, at 10 to 20°CA BTDC NOx highest, and approximately to the conventional diesel engine, NOx reduction when injection timing advanced. [ABSTRACT FROM AUTHOR]

Inspired by the works of López et al. [21] and the recent paper of Dang et al. [15], we devise a new inertial relaxation of the CQ algorithm for solving Split Feasibility Problems (SFP) in real Hilbert spaces. Under mild and standard conditions we establish weak convergence of the proposed algorithm. We also propose a Mann-type variant which converges strongly. The performances and comparisons with some existing methods are presented through numerical examples in Compressed Sensing and Sparse Binary Tomography by solving the LASSO problem. [ABSTRACT FROM AUTHOR]

Gel-derived Ag-TiO2-SiO2 nanomaterials were prepared by sol-gel process to determine their disinfection efficiency under UV-C, UV-A, solar irradiations and in dark condition. The surface morphology and properties of gel-derived Ag-TiO2-SiO2 nanomaterials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET specific surface area. The results showed that the average particle size of Ag-TiO2-SiO2 was around 10.9-16.3 nm. SiO2 mixed with TiO2 (the weight ratio of Si to Ti = 10:90) in the synthesis of Ag-TiO2-SiO2 by sol-gel process was found to increase the specific surface area of the obtained photocatalyst (164.5 m²g-1) as compared with that of commercial TiO2(P25) (53.1 m²g-1). Meanwhile, Ag doped in TiO2 (the mole ratio of Ag to TiO2 = 1%) decreased the specific surface area to 147.3 m&#178g-1. The antibacterial activities of gel-derived Ag-TiO2-SiO2 nanomaterials were evaluated by photocatalytic reaction against Escherichia coli bacteria (ATCC®25922). Ag-TiO2-SiO2 nanomaterials was observed to achieve higher disinfection efficiency than the catalyst without silver since both Ag nanoparticles and ions exhibit a strong antibacterial activity and promoted the e- 0 h+ separation of TiO2. The bactericidal activity of Ag-TiO2-SiO2 nanomaterial under light irradiation was superior to that under dark and only light. The reaction time to achieve a reduction by 6 log of bacteria of UV-C light alone and Ag-TiO2-SiO2 with UV-C light irradiation were 30 and 5 minutes, respectively. In addition, the superior synergistic effect of Ag-TiO2-SiO2 under both UV-A and solar light as compared to that under UV-C counterpart could be ascribed to the red-shift of the absorbance spectrum of the Ag doped TiO2-based catalyst. [ABSTRACT FROM AUTHOR]