Minimization of power losses in hybrid electric vehicles in view of the prolonging of battery life

Hybrid Electric Vehicles (HEVs) are becoming more popular than pure electric ones, nowadays. This is because of their better performance, economic advantages and higher operating range. However, their potential advantages extremely depend on their system design, most importantly their battery system design. Batteries’ life requirements as well as the cost of replacing them at the end of their life period, currently limit manufacturers to bring HEVs into play, even though their fuel economy reduces their everyday cost considerably. Generally, inappropriate discharge/charge patterns would result in loss in batteries’ life. In the present study, an optimization based control strategy has been proposed for the series HEVs in order to maximize the efficiency of the power-train while minimizing the loss. A genetic algorithm is implemented to optimally evaluate the control algorithm's parameters. The approach is then compared to two main control strategies, namely thermostatic control strategy and power follower control strategy. The computational procedure of the genetic algorithm is discussed, and a simulation study based on a model of a series hybrid electric vehicle is given to validate the genetic algorithm results.     

Synthesis of nano-structured lanthanum tungstates photocatalysts

Nano-particles of lanthanum tungstate were prepared through an optimized chemical precipitation reaction using the aqueous solutions of the ingredients. The optimization of the procedure was performed based on performing the so-called Taguchi robust design. The effects of various conditions influencing the size of the produced particles were evaluated using an orthogonal array. The optimally prepared lanthanum tungstate particles were found to be about 31 nm in diameter. The chemical and physical properties of the products were studied through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, UV–Vis and Fluorescence. Also the band gap energy of the produced nanoparticles was assessed through UV–Vis diffuse reflectance spectroscopy. The optimally prepared nano-structures were evaluated as photocatalysts in the pho-degradation of methylene blue.     

Effect of solution pH and adsorbent concentration on the sensing parameters of TGN‐based electrochemical sensor

The response of trilayer graphene nanoribbon (TGN)‐based ion‐sensitive field‐effect transistor (ISFET) to different pH solutions and adsorption effect on the sensing parameters are analytically studied in this research. The authors propose a TGN‐based sensor to electrochemically detect pH. To this end, absorption effect on the sensing area in the form of carrier concentration, carrier velocity, and conductance variations are investigated. Also, the caused electrical response on TGN as a detection element is analytically proposed, in which significant current decrease of the sensor is observed after exposure to high pH values. In order to verify the accuracy of the model, it is compared with recent reports on pH sensors. The TGN‐based pH sensor exposes higher current compared to that of carbon nanotube (CNT) counterpart for analogous ambient conditions. While, the comparative results demonstrate that the conductance of proposed model is lower than that of monolayer graphene‐counterpart for equivalent pH values. The results confirm that the conductance of the sensor is decreased and V_g‐min is obviously right‐shifted by increasing value of pH. The authors demonstrate that although there is not the experimental evidence reported in the part of literature for TGN sensor, but the model can assist in comprehending experiments involving nanoscale pH sensors.Inspec keywords: adsorption, graphene, ion sensitive field effect transistors, nanoribbons, electrochemical sensors, pH measurement, nanosensors, absorptionOther keywords: adsorbent concentration, TGN‐based electrochemical sensor, trilayer graphene nanoribbon‐based ion‐sensitive field‐effect transistor, adsorption effect, carbon nanotube counterpart, monolayer graphene‐counterpart, nanoscale pH sensors, pH solution effect, TGN‐based pH sensor, ISFET, CNT, C     

Flooding and drop size in a pulsed disc and doughnut extraction column

The hydrodynamic behavior of a pulsed disc and doughnut column has been investigated using three different systems in the absence of mass transfer. Sauter-mean drop diameter (d₃₂), flooding velocity and holdup at flooding have been measured at different operating conditions. The following operating variables have been studied: pulsation intensity and flow rate of both liquid phases. As expected, smaller mean drop sizes are obtained with the increase of pulsation intensity. The results also show no significant effect of continuous phase flow rate on mean drop size, which increases with increase of dispersed phase flow rate for the operating conditions investigated. A single correlation for the prediction of d₃₂ in the mixer-settler, transition and emulsion regimes of operation is proposed with a mean deviation of 7.32%. The maximum throughput is influenced mainly by pulsation intensity and interfacial tension. Two precise correlations are proposed for predicting flooding velocities in this column. The first is based on operating variables, column geometry, and system physical properties. The second one considers the same variables, except column geometry. Good agreement between prediction and experiments is found for all operating conditions investigated.     

Sweeping Gas Membrane Distillation (SGMD) as an Alternative for Integration of Bioethanol Processing: Study on a Commercial Membrane and Operating Parameters

This article considers the application of the sweeping gas membrane distillation process (SGMD) for direct separation of ethanol-water using a flat sheet PTFE membrane. It also studies the effect of operating parameters including feed concentration, feed temperature, feed flow rate, and sweeping gas flow rate on the permeation flux and selectivity of ethanol/water. The results showed that the increase in feed temperature increases in permeate flux and selectivity. Selectivities of 18.5 to 25 were achieved using dilute feeds within the temperature range of 35 to 55°C. However, by increasing the feed concentration by more than 5 wt.%, the selectivity was decreased. The increase in permeation flux and ethanol selectivity at higher feed flow rates was mainly due to the reduction of polarization effects. Moreover, the PTFE membrane was characterized by AFM. The results showed that the present process could be used as a stand-alone technique for bioethanol process integration.     

Prediction of fluid pattern in a shear flow on intelligent neural nodes using ANFIS and LBM

Neural Computing and Applications - Prediction of fluid pattern inside chemical mixing tanks and reactors is very challenging, mainly when scale-up and optimization of devices are essential due to...     

Assessment of supercapacitive performance of europium tungstate nanoparticles prepared via hydrothermal method

Nano-sized europium tungstate particles were prepared by reacting europium nitrate hexahydrate and sodium tungstate solutions, and the structures, morphology and optical properties of the product were evaluated by XRD, FT-IR, SEM, and UV–Visible techniques. The Eu₂(WO₄)₃ nanoparticles were evaluated as potential materials for constructing supercapacitor electrodes using the results of cyclic voltammetry, galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy and the electrodes were found to have a specific capacitance (SC) value of 347 F g^?1 in a 2.0 M H₂SO₄ electrolyte at a scan rate of 2 mV s^?1. The electrodes were further studied at the GCD at a current density of 1 A g^?1, and the SC of the building material was found to be 282 F g^?1. The cycling durability of the electrodes was also found to be excellent. After 4000 cycles the SC values of the electrodes were found to reach 129%. The preparation method and the resulting nano-particles, were hence found to be promising for high performance energy applications.     

Topology optimization of geometrically nonlinear structures using an evolutionary optimization method

The topology optimization using isolines/isosurfaces and extended finite element method (Iso-XFEM) is an evolutionary optimization method developed in previous studies to enable the generation of high-resolution topology optimized designs suitable for additive manufacture. Conventional approaches for topology optimization require additional post-processing after optimization to generate a manufacturable topology with clearly defined smooth boundaries. Iso-XFEM aims to eliminate this time-consuming post-processing stage by defining the boundaries using isovalues of a structural performance criterion and an extended finite element method (XFEM) scheme. In this article, the Iso-XFEM method is further developed to enable the topology optimization of geometrically nonlinear structures undergoing large deformations. This is achieved by implementing a total Lagrangian finite element formulation and defining a structural performance criterion appropriate for the objective function of the optimization problem. The Iso-XFEM solutions for geometrically nonlinear test cases implementing linear and nonlinear modelling are compared, and the suitability of nonlinear modelling for the topology optimization of geometrically nonlinear structures is investigated.     

Impregnated of C6CoFeN6 nanoparticles in poly-1-naphthol for uptake of Cs(I) from aqueous waste

To carry out our research, C₆CoFeN₆@poly-1-naphthol nanoparticles were synthesized and characterized by SEM, X-ray diffraction, Fourier transform infrared, thermogravimetric analysis and Brunauer–Emmett–Teller (BET) analyses. The SEM images indicate that the average particle sizes are about 60 nm in diameter. The BET result provides a clear evidence for the high surface area of the sample 180.6 m²/g. Cs(I) ions removed from the aqueous solution in a batch mode using CoHCF@poly-1-nanphtol as an adsorbent. The adsorption effecting parameters such as the solution pH, initial Cs(I) concentration, contact time and temperature were studied. Maximum sorption capacity for the nanocomposite was found to be 200.5 mg/g at 1000 mg/g, pH = 5 and 298 K. The time-adsorption dependence studies indicated that the maximum Cs(I) uptake was within the initial 40 min contact time and the adsorption mechanism was governed by the double exponential model. The equilibrium sorption data fitted well to the Freudlich model with n ? 1 indicating a stronger interaction and high affinity of C₆CoFeN₆@poly-1-naphthol for Cs(I) ions. The thermodynamic parameters, including changes in Gibbs free energy, entropy and enthalpy, were determined. The results indicated that CoHCF–poly-1-nanphtol could be a potential adsorbent for the uptake of Cs(I) ions from an aqueous solution.     

Immobilization of organophosphorus hydrolase enzyme by covalent attachment on modified cellulose microfibers using different chemical activation strategies: Characterization and stability studies

The plant cellulose powder was activated by two different methods using 1,4-butanediol diglycidyl ether(BTDE)and 1,1′-Carbonyldiimidazole(CDI) as the chemical coupling agents.Organophosphorus hydrolase(OPH) from Flavobacterium ATCC 27551 was immobilized on any of activated support through covalent bonding.The optimal conditions of affecting parameters on enzyme immobilization in both methods were found, and it was demonstrated that the highest activity yields of immobilized OPH onto epoxy and CDI treated cellulose were 68.32%and 73.51%, respectively.The surface treatment of cellulose via covalent coupling with BTDE and CDI agents was proved by FTIR analysis.The kinetic constants of the free and immobilized enzymes were determined, and it was showed that both immobilization techniques moderately increased the Kmvalue of the free OPH.The improvements in storage and thermal stability were investigated and depicted that the half-life of immobilized OPH over the surface of epoxy modified cellulose had a better growth compared to the free and immobilized enzymes onto CDI treated support.Also, the pH stability of the immobilized preparations was enhanced relative to the free counterpart and revealed that all enzyme samples would have the same optimum pH value for stability at 9.0.Additionally, the immobilized OPH onto epoxy and CDI activated cellulose retained about 59% and 68% of their initial activity after ten turns of batch operation, respectively.The results demonstrated the high performance of OPH enzyme in immobilized state onto an inexpensive support with the potential of industrial applications.