Bio-oils have been known with some advantages such as biodegradability, renewable, oxygen content, no-sulfur content. However, high viscosity, high surface tension and density due to the large ...structure may be the main causes strongly affecting the spray characteristics, mixture formation, combustion process, and emission characteristics of diesel engines running on bio-oils. In this work, the evaluation of the relationship between the spray parameters of used bio-oils including spray penetration (S) and cone angle (ɸ), and preheating temperature compared to fossil diesel fuel was conducted. Besides, the influence of the spray parameters on the breakup mechanism, brake thermal efficiency (ηe), heat release rate (HRR), and emission characteristics of an 80hp-diesel engine was reported. As a result, pure bio-oil was preheated to 105 °C to achieve the similarity of some physical properties and spray parameters compared to diesel fuel, but emission parameters of carbon monoxide (CO) and unburnt hydrocarbon (UHC) were 23.10% and 23.36% respectively higher. Meanwhile, brake thermal efficiency (ηe), and emissions of CO2, NOx, smoke were 3.36%, and 12.00%, 8.86%, 48.48% respectively lower than those of fossil diesel fuel. The findings in this paper showed further evidence in the direct use of pure biodiesel as a fuel for diesel engines.
•The heating method is used to improve the disadvantages of bio-oils.•Spray characteristics of preheated bio-oils to 80–110 °C are determined.•Engine performance and exhaust gas temperature are measured and analyzed.•The optimum heating temperature for as-used bio-oils is 105 °C.•An exhaust gas-electricity integration system is fabricated for experimental purpose.
Novel zinc anodes are synthesized via electroplating with organic additives in the plating solution. The selected organic additives are cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate ...(SDS), polyethylene-glycol (PEG-8000), and thiourea (TU). The synthesized zinc anode materials, namely, Zn-CTAB, Zn-SDS, Zn-PEG, and Zn-TU, are characterized by powder X-ray diffraction and scanning electron microscopy. The results show that each additive produces distinctively different crystallographic orientation and surface texture. The surface electrochemical activity is characterized by linear polarization when the zinc is in contact with the battery’s electrolyte. Tafel fitting on the linear polarization data reveals that the synthetic zinc materials using organic additives all exhibit 6–30 times lower corrosion currents. When using Zn-SDS as the anode in the rechargeable hybrid aqueous battery, the float current decreases as much as 2.5 times. The batteries with Zn-SDS, Zn-PEG, and Zn-TU anodes display the capacity retention of 79%, 76%, and 80% after 1000 cycles of charge–discharge at 4C rate, whereas only 67% obtained from the batteries using the anode prepared from commercial zinc foil. Among these electroplated anodes, Zn-SDS is the most suitable for aqueous batteries thanks to its low corrosion rate, low dendrite formation, low float current, and high capacity retention after 1000 cycles.
Rechargeable aqueous Zn-MnO2 batteries are a promising candidate for large-scale energy storage systems due to their outstanding advantages, such as high energy density, high safety, low cost, and ...environmental friendliness. Considering the controversies surrounding the mechanism of this battery containing a mildly acidic electrolyte, the electrochemical behavior of this type of battery using β-MnO2 as the cathode is systematically investigated. The results indicate that the reversible intercalation of Zn2+ ions into MnO2 is not likely to take place in the aqueous system. We conclude that it is the existence of the water molecule and its participation in the electrochemical reactions, for instance, the reversible insertion of proton into MnO2 and the electrolysis of water, that makes the mechanism of aqueous Zn-MnO2 batteries complicated. Besides, the capacity fading of this mildly acidic Zn-MnO2 battery is assigned to the generation of the inert layer of Zn4SO4(OH)6·nH2O and the ZnMn2O4 on the cathode via electrochemical conversion reactions, the dissolution of the active material during discharging, and the release of gases. When Mn2+ ions are available in the electrolyte, they will be electrodeposited on the cathode during charging, and the kinetics of the electrochemical reactions of the electrode is improved, leading to the higher electrochemical performance of the battery.
Heavy metal pollution remains a global environmental challenge that poses a significant threat to human life. Various methods have been explored to eliminate heavy metal pollutants from the ...environment. However, most methods are constrained by high expenses, processing duration, geological problems, and political issues. The immobilization of metals, phytoextraction, and biological methods have proven practical in treating metal contaminants from the soil. This review focuses on the general status of heavy metal contamination of soils, including the excessive heavy metal concentrations in crops. The assessment of the recent advanced technologies and future challenges were reviewed. Molecular and genetic mechanisms that allow microbes and plants to collect and tolerate heavy metals were elaborated. Tremendous efforts to remediate contaminated soils have generated several challenges, including the need for remediation methodologies, degrees of soil contamination, site conditions, widespread adoptions and various possibilities occurring at different stages of remediation are discussed in detail.
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•Impact of heavy metal toxicity towards the environment and human health.•Physical, chemical, and bioremediation approaches were used for contaminated soils.•Land filling, soil cleaning and solidification methods are well-established.•Treatability studies are crucial in the selection of soil sanitation techniques.•Future prospect and challenges of remediation would provide insights for readers.
The synthesis of novel zinc electrodes has been successfully implemented by using the electroplating method with the aid of inorganic additives in the electroplating solution. The selected inorganic ...additives are indium sulfate, tin oxide, and boric acid. From X‐ray diffraction results, these synthesized zinc electrodes prefer (002) and/or (103) crystallographic orientations, representing basal morphology and high resistance to dendrite growth. The corrosion rates of these electroplated zinc samples decrease as much as 11 times smaller than the corrosion rate on zinc foil when the zinc materials are in contact with the aqueous electrolyte of a rechargeable hybrid aqueous battery (ReHAB). The ReHABs employing these anodes exhibit up to a threefold decrease in float charge current density after a seven‐day constant‐voltage charging at 2.1 V versus Zn2+/Zn. Furthermore, the capacity retention is up to 15 % higher than the performance of battery containing commercial Zn after 1000 cycles of charge–discharge. The significant advancements are attributed to the careful preparation of the anode, which contains appropriate crystallographic orientation and morphology.
Enhanced battery performance in cyclability and float charge current density is observed when the anodes used are electroplated zinc. These were prepared using indium sulfate, tin oxide, or boric acid additives in the electroplating solution.
Currently, the development of alternative and green energy sources has been being strongly pushed aiming to recoup the lack of fossil energy, to meet the ever-increasing demand of energy use in ...modern society, and to palliate concerns regarding environmental pollution and global climate change. Therefore, producing energy from biomass sources has recently been of great interest because biomass is considered as a reliable and ubiquitous source. Indeed, the conversion of biomass into furan derivatives through the catalytic production process is emerging as a fascinating and promising method. Being one of the furan-based compounds, 2-Methylfuran (MF) is known as a critical platform substance and an ideal green solution on the pathway of finding alternative fuels because the MF properties are similar to those of fossil fuels and MF could be generated from renewable biomass source. In this review paper, the process of MF synthesis from biomass through catalyst reactions was thoroughly analyzed. More importantly, the pyrolysis and oxidation progress of MF was also critically presented aiming to clarify the applicability of MF to internal combustion engines. Finally, the performance, the characteristics of combustion, and pollutant formation of internal combustion engines fueled with MF were discussed in detail. In general, MF could become a promising alternative fuel for internal combustion engines although studies on the engine durability, compatibility to materials, tribology behaviors should be further carried out in the future.
•Catalyst-based MF synthesis from biomass through furfural was critically presented.•Pyrolysis progress, combustion, and ignition behaviors were thoroughly analyzed.•Key characteristics of engines fueled with MF-based fuels were discussed in detail.•Economic aspect, existing challenges, and future perspective were mentioned.
Shear strength of the soil is an important engineering parameter used in the design and audit of geo-technical structures. In this research, we aim to investigate and compare the performance of four ...machine learning methods, Particle Swarm Optimization - Adaptive Network based Fuzzy Inference System (PANFIS), Genetic Algorithm - Adaptive Network based Fuzzy Inference System (GANFIS), Support Vector Regression (SVR), and Artificial Neural Networks (ANN), for predicting the strength of soft soils. For this purpose, case studies of 188 plastic clay soil samples collected from two major projects, Nhat Tan and Cua Dai bridges in Viet Nam have been used for generating training and testing datasets for constructing and validating the models. Validation and comparison of the models have been carried out using RMSE, and R. The results show that the PANFIS has the highest prediction capability (RMSE = 0.038 and R = 0.601), followed by the GANFIS (RMSE = 0.04 and R = 0.569), SVR (RMSE = 0.044 and R = 0.549), and ANN (RMSE = 0.059 and R = 0.49). It can be concluded that out of four models the PANFIS indicates as a promising technique for prediction of the strength of soft soils.
•We concentrated on the prediction of the shear strength of soft soils.•xANN were used.•Case studies of 188 plastic clay soil samples in Viet Nam have been used.•PANFIS indicates as a promising technique for prediction of strength of soft soils.
•Used fuels including preheated and unpreheated Jatropha oil, diesel fuel.•Impacts of triple-physical properties of fuel on atomization, breakup, and combustion.•Trilateral correlation of deposits, ...spray characteristics, and engine performance.•Thorough analysis on the relation of accumulated deposits and pollutant emissions.•Dependence of spray penetration and cone angle on formed deposits and fuel properties.
The benefits and advantages of bio-based fuels according to the research results of scientists and researchers related to the stable maintenance and sustainable development for the purpose of harmonizing the environment and life is an indisputable fact. Experimental studies on the use of bio-based fuels for engines in the long term should be thus thoroughly conducted to obtain the fullest results of economic-technical features and emissions, to name just a few. In this paper, a state-of-the-art analysis on the core correlation based on the trilateral relationship of spray characteristics, combustion, and emissions of a high-speed four-stroke diesel engine running on Jatropha oil (JO) in two cases of preheated and unpreheated in comparison to diesel fuel was investigated and carried out. Tests included two phases: (i)-tests of spray characteristics, analysis of combustion and emissions for engine fueled with preheated JO, unpreheated JO, and DF at the first hour and after 300 h of endurance test for engine, (ii)-analysis of formed deposits in the nozzle orifices and piston crown after 300 h of operation. As a result, huge deposits formed in the injector orifices and piston crown based on optical observation by SEM in case of using unpreheated JO as fuel were found, followed by preheated JO and DF. In addition, a sharp increase in spray penetration length and a significant decrease of cone angle for unpreheated JO compared to preheated JO and DF were also indicated, whereas thermal efficiency of the test engine for preheated JO, unpreheated JO, and DF was reduced by respectively 1.68%, 4.38%, and 0.98% after 300 h of operation. For emission data, negative changes such as a more reduction of NOx along with a higher augment of CO, HC, and smoke with unpreheated JO than those of preheated JO and DF were reported. In closing, core correlation as well as trilateral impacts of accumulated deposits, spray characteristics, and combustion were thoroughly demonstrated and deeply analyzed.
Phenolic compounds would be the emerging pollutant by 2050, because of their wide spread applicability in daily life and therefore the adoption of suitable detection methods in which identification ...and separation of isomers is highly desirable. Owing to the fascinating features, Metal-organic framework (MOF), a class of reticular materials holds a large surface area with tunable shape and adjustable porosity will provide strong interaction with analytes through abundant functional groups resulting in high selectivity towards electrochemical determination of phenolic isomers. Nevertheless, the sensing performance can still be further improved by building MOF network (intrinsic resistance) with functional (conducting) materials, resulting in MOF based nanocomposite. Herein, this review provides the summary of MOF based nanocomposites for electrochemical sensing of phenolic compounds developed from 2015. In this review, we discussed the demerits of pristine MOF as electrode materials, and the requirement of new class of MOF with functional materials such as nanomaterials, carbon nanotubes, graphene and MXene. The history and evolution of MOF nanocomposite-based materials are discussed and also featured the impressive physical and chemical properties. Besides this review discusses the factors influencing the conducting pathway and mass transport of MOF based nanocomposite for enhanced sensing performance of phenolic compounds with suitable mechanistic illustrations. Finally, the major challenges governing the determination of phenolic compounds and the future advancements required for the development of MOF based electrodes for various applications are highlighted.
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•Electrochemical sensing of phenolic compounds using MOF or MOF based nanocomposites are critically examined.•Development of MOF based electrodes for various applications are highlighted.•Challenges and opportunities using MOF based electrodes for electrochemical sensors were reviewed.
In this work, we examined the possibility on the application of rice husk as biosorbent for the elimination of heavy metal ions (chromium, lead, and zinc) existing in the aqueous solutions. The ...biosorbent was prepared from rice husk powder and modified with 0.1 N of HCl for creating the functional groups and increase specific surface area. The FT-IR spectra, SEM& EDX studies of rice hulls powder were examined for the pristine adsorbent and after the adsorption of heavy metal ions. The batch adsorption technique was adopted for this work and adsorption parameters were optimized. The maximum efficiency of adsorption is obtained at 6.0 pH, 1 h of contact duration, the rice husk dosage is 2.5 g/L, and temperature of 30°C for 25 mg/L of Cr, Pb & Zn metal ion solutions. The Cr, Pb & Zn metal ions are removed up to 87.12 %, 88.63 % & 99.28 %, respectively, using the rice husk powder. The adsorption process follows the Temkin & D-R isotherm model. Elovich model was fitted against the kinetic data of metal ion adsorption. Based on the experimental observations, the rice husk powder can be considered as a low cost adsorbent for heavy metal ion removal from the industrial effluent.
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•This experimental study provides the details of the production of low cost adsorbent material from rice husk powder.•Adsorptive removal of Cr, Pb & Zn metal ions was investigated by batch mode.•The maximum adsorption efficiency of 87.12% for chromium, 88.63 % for lead and 99.28 % for zinc heavy metal ions was attained.•The maximum amount of desorption was attained by adding 0.2 N of HCl in the adsorbate material.
