The nanofibers membranes were fabricated by poly(vinyl alcohol)/chitosan (PVA/Chi) using an electro-spun technique for selective and high adsorption of lead (Pb(II)) and cadmium (Cd(II)) ions based ...on the solution acidity. The PVA/Chi NFs membranes were characterized systematically using several instrumentations. In addition, several experimental parameters such as initial metal ions concentration, interaction time, adsorbent dosage, solution pH and the effects of competing ions on Pb(II) and Cd(II) adsorption were evaluated. The adsorption data were also clarified that the PVA/Chi NFs membranes were exhibited high kinetic performances towards the both toxic ions at the optimum conditions. The adsorption data were manipulated using different kinetics models, and it was confirmed that only pseudo-second-order model obeyed the adsorption kinetics for Pb(II) and Cd(II) ions. Similarly, the equilibrium data were well fitted with the Langmuir adsorption isotherms model, and the maximum adsorption capacity was 266.12 and 148.79 mg/g for Pb(II) and Cd(II) ions, respectively. The Pb(II) and Cd(II) ions adsorptions were also measured to know the selectivity with simulated environmental solution, and the data were confirmed the high selectivity to Pb(II) and Cd(II) ions at the optimum condition and the nanofibers membrane shown the potentiality for possible use in efficient removal of the selected toxic ions from waste samples. Thus, the PVA/Chi NFs are considered to be effective and promising materials for Pb(II) and Cd(II) ions from wastewaters with high efficiency.
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•Poly(vinyl alcohol)/chitosan nanofiber was fabricated for Pb(II) & Cd(II) removal from wastewater.•The adsorption was not affected in the presence of competing ions.•The adsorption study was most appropriated with the Langmuir isotherm model.•The high adsorption capacity of Pb(II) and Cd(II) was 266.0 and 148.0 mg/g, respectively.
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•Sensitive and reliable detection of commonly used food additive tert-butylhydroquinone.•Prepared ZnCuMg TMO/β-CD-CB hybrid nanocomposite based on sonochemical ...approach.•Nanomolar-level detection limit and high sensitivity was achieved for the proposed TBHQ sensor.•Real sample analysis was conducted in edible oil samples to ensure practical feasibility of TBHQ detection.
It is pivotal to precisely detect food preservatives to ascertain food quality and safety. In this work, we report the sensitive electrochemical detection of widely used cytotoxic food preservative tert-butylhydroquinone (TBHQ). A novel nanocomposite was sonochemically prepared by embedding ternary metal oxide (TMO) comprising ZnO, CuO, and MgO in β-cyclodextrin (β-CD) functionalized carbon black (CB). The properties of the prepared nanocomposite were evaluated by employing multiple characterization methods. The nanocomposite fabricated on a screen printed carbon electrode exhibited exceptional electrocatalytic activity towards TBHQ detection, evident from the resultant very low detection limit of 1 nM and high sensitivity of 22.67 μA μM−1 cm−2. Moreover, the developed TBHQ sensor evinced all the important traits of a good electrochemical sensor including excellent selectivity, stability, reproducibility, and repeatability. Furthermore, for validating practical feasibility of TBHQ detection, we successfully determined this food additive in edible oils.
Nanomolar-level detection of priority toxic pollutant 4-nitrophenol (4-NP) in environment using a novel ternary nanocomposite based electrochemical sensor and its photocatalytic degradation is ...reported in this paper. A non-toxic and renewable natural biopolymer, chitosan wrapped carbon nanofibers was embedded with Ag doped spinel Co3O4 to prepare the bi-functional ternary nanocomposite. Economical and ecofriendly sonochemical method was employed in preparation of this porous nanocomposite. We used one-pot aqueous solution approach to synthesize Ag–Co3O4 nanoflowers and ultrasound-assisted method was utilized to prepare CS-CNFs. Morphological and structural properties of synthesized materials were analyzed using different characterization techniques. Electrochemical investigations using cyclic voltammetry and differential pulse voltammetry carried out with prepared ternary nanocomposite modified carbon electrode revealed its outstanding electrocatalytic activity in 4-NP quantification. The developed 4-NP sensor showcased excellent sensitivity of 55.98 μAμM−1cm−2 and nanomolar detection limit of 0.4 nM. Moreover, reproducibility, repeatability, stability, and selectivity were evaluated to confirm reliability of developed sensor. Further, real sample analyses were conducted using domestic sewage, underground water, and tomato to affirm the practical feasibility of 4-NP detection using the proposed sensor.
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•Sensitive detection of highly hazardous nitroaromatic compound at nanomolar level.•Bi-functional Ag–Co3O4 NFs/CS-CNFs was prepared using sonochemical approach.•Photocatalytic degradation of 4-nitrophenol using novel bi-functional nanocomposite.•Real sample analyses conducted in domestic sewage, underground water, and tomato.
Synthetic food colorants are extensively used across the globe regardless of the fact that they induce deleterious side effects when used in higher amounts. In this work, a novel electrochemical ...sensor based on nickel nanoparticles doped lettuce-like Co3O4 anchored graphene oxide (GO) nanosheets was developed for effective detection of sulfonated azo dye sunset yellow widely used as a food colorant. Hydrothermal synthesis was adopted for the preparation of lettuce-like spinel Co3O4 nanoparticles and Ni-Co3O4 NPs/GO nanocomposite was prepared using ecofriendly and economical sonochemical method. The prepared ternary nanocomposite meticulously fabricated on a screen-printed carbon electrode exhibited remarkable electrocatalytic activity towards sunset yellow determination. This is apparent from the resultant well-defined and intense redox peak currents of Ni-Co3O4 NPs/GO nanocomposite modified electrode at very low potentials. The developed sunset yellow sensor exhibited a high sensitivity of 4.16 μA μM−1 cm−2 and a nanomolar detection limit of 0.9 nM in the linear range 0.125–108.5 μM. Furthermore, experiments were conducted to affirm excellent stability, reproducibility, repeatability, and selectivity of proposed sensor. The practicality of sunset yellow determination using the developed sensor was analyzed in different varieties of food samples including jelly, soft drink, ice cream, and candy resulting in recovery in the range of 96.16%–102.56%.
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•Toxic azo dye sunset yellow FC used as common food colorant was detected at nanomolar level.•Lettuce-like Co3O4 decorated by Ni nanoparticles was anchored on GO for nanocomposite preparation.•Remarkable electrocatalytic activity was showcased by novel ternary nanocomposite fabricated on SPCE.•Practicality of sunset yellow detection was evaluated in jelly, soft drink, ice cream, and candy.
The viscoelastic fluid flow over a non linear stretching porous sheet is considered in this analysis. The case of suction and injection is also discuused. The effects of thermophoresis and brownain ...motion with viscous dissipation is taken into account. Under the flow assumptions, boundary layer approximation applied on the mathematical model and developed the partial differential equations. The similarity variable is applied on the partial differential equations which converted into ordinary differential equations. The dimensionless system further solved through numerical technique bvp4c method. The results of the current problem achieved after solving the problem which presented through graphs and table. Influence of numerous physical parameters on velocity function, concentration function and temperature function are manipulated through graphs. The tabular results are schemed to display skin friction and local Nusselt number. The higher values of Nb which enhanced the velocity profile but declines velocity profile due to higher values of Ec. The thermal thickness enhances due larger values of γ and Pr but thermal thickness declines due to higher values of Ec and Nt. The concentration profile enhances due to enhancing the values of Ec and Pr but concentration profile declines due to increasing the values of Nt. Nusselt number enhaced due to higher values of Ec,Sc and Nt but declines of higher values of Pr.
Improvement of the electrocatalytic activity of nickel toward methanol oxidation can be conducted by exploiting the synergetic influence of a co-catalyst and/or utilizing a proper support. In this ...study, utilizing tin as a co-catalyst and supporting on carbon nanofibers are proposed to enhance methanol oxidation in the alkaline media. Typically, NiSn nanoparticles alloy-incorporated carbon nanofibers could be prepared by calcination of electrospun nanofibers composed of poly (vinyl alcohol), nickel acetate tetrahydrate and tin chloride under argon atmosphere at a high temperature. The influence of the co-catalyst content and the calcination temperature on the morphology, composition and electrocatalytic activity of the proposed nanofibers was investigated. Smooth electrospun nanofibers can be prepared regardless the tin chloride content up to 35 wt%, and the calcination process did not distinctly affect the nanofibrous morphology. Mostly, Ni3Sn and Ni3Sn2 nanoparticles-incorporated amorphous carbon nanofibers were obtained at all the utilized calcination temperatures (700, 850 and 1000 °C) and examined SnCl2 contents. However, at 10 wt% SnCl2 content and 850 °C calcination temperature, single metallic compound (Ni3Sn2)-incorporated carbon nanofibers were synthesized. Electrochemical measurements indicated that the electrocatalytic activity depends strongly on the tin content as well as the calcination temperature. The nanofibers obtained from electrospun solution containing 10 wt% SnCl2 and calcined at 850 °C showed very good performance compared to the other formulations. Typically, the corresponding onset potential of the methanol oxidation reaction using these nanofibers catalyst is 315 mV (vs. Ag/AgCl) while it was 405 mV for the nanofibers obtained from electrospun solution containing 0, 5, 15, 25 and 35 wt% SnCl2. Moreover, the best nanofibers reveal the highest current density. Kinetic study indicated that the corresponding activation energy is 15.6 kJ/mol.
•NiSn-incorporated CNFs are introduced as effective electrocatalyst for methanol oxidation.•Tin co-catalyst shows very good performance at 10 wt% content.•The calcination temperature was optimized; 850 °C is the best.•The activation energy was estimated.
•Van der Waals p-system in the viscosity capillarity version is discussed.•Auxiliary equation mapping algorithm is implemented.•Painleve test is used to check integrability of model.•Some new ...solitary wave solutions are obtained successfully.
This work proposes two well known schemes, painleve analysis test and auxiliary equation mapping (AEM) algorithm to find new solitary wave solutions for van der Waals p-system (VDW) in the viscosity capillarity version. For the clarity of physical features, new solitary wave solutions like periodic, kink and anti kink type, doubly periodic, trigonometric, singular, rational, combined soliton like solutions and hyperbolic solutions, etc. are articulated coupled with graphically patterns 2D, 3D and density plots to visualize the dynamics of our model. This study reveals that the methods used are simple, reliable, unambiguous and concise as compared to many other techniques for solving nonlinear partial differential equations (NLPDE). A new direct way to solve NLPDEs is provided using this approach. The method allows one to obtain new accurate solutions of the solitary wave that cannot be obtained using other methodologies, and it can be implemented on a computer using computer algebraic systems such as Mathematica or Maple.
Poly(ethylene terephthalate)/graphite (PET/G) micro-composites were fabricated by the melt compounding method using a minilab extruder. The carbon fillers were found to act as nucleating agents for ...the PET matrix and hence accelerated crystallization and increased the degree of crystallinity. TGA showed that carbon fillers improved the resistance to thermal and thermo-oxidative degradation under both air and nitrogen atmospheres. However, a poor agreement was observed at higher loadings of the filler where the composites displayed reduced reinforcement efficiency. The results demonstrate that the addition of graphite at loading >14.5 wt.% made electrically conductive composites. It was calculated that the electric conductivities of PET/graphite micro-composites were enhanced, above the percolation threshold values by two orders of magnitudes compared to the PET matrix. The minimum value of conductivity required to avoid electrostatic charge application of an insulating polymer was achieved, just above the threshold values. The addition of graphite also improved thermal stability of PET, accelerated its crystallization process and increased the degree of crystallinity. Microscopic results exhibit no indication of aggregations at 2 wt.% graphite, whereas more agglomeration and rolling up could be seen as the graphite content was increased in the PET matrix (in particular, above the percolation threshold value). Furthermore, based on the mechanical experimental characterization of the PET/graphite micro-composites, a large deformation-based mathematical model is proposed for material behavior predictions. The model fits well the experimental data and predicts other mechanical data that are not included in the parameter identification.
•The blood is modelled as non-Newtonian Casson fluid.•The velocities of blood and magnetic particles are highly influenced by the fractional order parameter.•In general, the particle velocity is ...lower than the blood velocity.•The blood and particle velocities increase with respect to Reynold number and Casson fluid parameters.•The blood velocity decreases with respect to Hartmann number.
Arterial diseases would lead to several serious disorders in the cardiovascular system such as atherosclerosis. These disorders are mainly caused by the presence of fatty deposits, cholesterol and lipoproteins inside blood vessel. This paper deals with the analysis of non-Newtonian magnetic blood flow in an inclined stenosed artery.
The Casson fluid was used to model the blood that flows under the influences of uniformly distributed magnetic field and oscillating pressure gradient. The governing fractional differential equations were expressed using the Caputo Fabrizio fractional derivative without singular kernel.
The analytical solutions of velocities for non-Newtonian model were then calculated by means of Laplace and finite Hankel transforms. These velocities were then presented graphically. The result shows that the velocity increases with respect to Reynolds number and Casson parameter, while decreases when Hartmann number increases.
Casson blood was treated as the non-Newtonian fluid. The MHD blood flow was accelerated by pressure gradient. These findings are beneficial for studying atherosclerosis therapy, the diagnosis and therapeutic treatment of some medical problems.
The current investigation deals with the numerical simulation of cross‐flow of non‐Newtonian fluid. Flow dynamics are studied by considering a uniform channel bounded by porous walls. Transversely ...acting magnetic fields have also been taken into account on the two‐dimensional flow of Tangent‐Hyperbolic fluid. Skin friction is addressed by employing the lubrication effects on the porous channel. In addition to this, Fourier's law of conduction is incorporated to highlight the heating effects which attenuates the shear thickening posture of the fluid. Highly nonlinear and coupled differential equations are solved numerically by using the Runge‐Kutta method with shooting technique. Thermal and momentum transport is simulated by generating the numerical MATLAB codes. Study reveals that slippery porous walls/channels can effectively be used in chemical and mechanical industries which deal with various kinds of highly viscous flows. Moreover, more energy is contributed by Peclet number and viscous heating parameter and improve the heat transfer rate.
The current investigation deals with the numerical simulation of cross‐flow of non‐Newtonian fluid. Flow dynamics are studied by considering a uniform channel bounded by porous walls. Transversely acting magnetic fields have also been taken into account on the two‐dimensional flow of Tangent‐Hyperbolic fluid. Skin friction is addressed by employing the lubrication effects on the porous channel. In addition to this, Fourier's law of conduction is incorporated to highlight the heating effects which attenuates the shear thickening posture of the fluid.…
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