Numerical solution for Sisko nanofluid flow through stretching surface in a Darcy–Forchheimer porous medium with thermal radiation

The heat transfer assessments in a Sisko nanofluid flow over a stretching surface in a Darcy–Forchheimer porous medium with heat generation and thermal radiation are studied. The numerical analysis technique is used to assess the governing nonlinear equations of the model. The influence of Forchheimer number, porosity, heat generation, radiation, and material parameters is examined. The outlines of Nusselt number and skin friction coefficient corresponding to pertinent parameters are revealed. The comparison of Nusselt number outlines of working fluid and Newtonian fluid is depicted. From the analysis, it has been examined that with the increase in Forchheimer number and material parameter values, heat transfer function decreases, whereas heat transfer characteristics of Sisko nanofluid increase with heat generation and material parameters. Moreover, working fluid velocity outlines depreciate when there is an increase in porosity parameter for both shear-thinning and shear-thickening. The comparison of this study with previous research has been conducted.     

Development and quality characteristics of functional Kulfi fortified with microencapsulated betalains

Fruit and vegetable waste valorisation has opened opportunities for the utilisation of food waste for extraction and development of valuable functional foods. Therefore, the study was designed to develop a functional Kulfi fortified with encapsulated betalains extracted from red beetroot (Beta vulgaris L.) pomace. Moreover, fortified functional Kulfi samples were studied for physico-chemical, antioxidant, microbiological and sensory analyses. Fortified functional Kulfi reported the higher antioxidant activity (64.88% and 75.27%) with reduced melting rate (1.84 mL min⁻¹ and 2.08 mL min⁻¹) and microbial profile (3.77 log CFU g⁻¹ and 3.14 log CFU g⁻¹) compared with control. Sensory analysis showed a no significant (P > 0.05) impact on the overall acceptability of functional Kulfi (7.25) compared with the commercial Kulfi (7.20), which was further confirmed by a bi-plot of principal component analysis. Overall, the encapsulated betalains improved the quality characteristics of functional Kulfi and could be used for the development of frozen dairy products.     

Comparison of Viscoelastic Properties of Set and Stirred Yogurts Made from High Pressure and Thermally Treated Milks

Viscoelastic properties of set and stirred yogurts made from raw (control), high pressure (300 and 400 MPa, 20 min, 4°C), and heat treated (80°C, 30 min) milks were investigated using a using a computer controlled rotational viscometer under oscillatory testing program, including three operating modes: a strain sweep, frequency sweep, and an isothermal time sweep. Linear, exponential, power-law, and Weltmann models were used to assess and describe the strain, frequency, and time dependent viscoelastic properties of yogurts. Their significance was analyzed using Duncan’s multiple range tests. The results indicated that the set yogurts had larger moduli (storage moduli G’ and loss moduli G”) and lower phase shift (tan δ) than stirred yogurts. High pressure treatment increased storage moduli G’ of both stirred and set yogurts significantly (p < 0.05). The influence on loss modulus was relatively lower. Unlike yogurts made from heat treated and raw milks, the ones made from pressure treated milks resulted in significantly different gel, frequency, and strain dependent properties for both types of yogurts. However, time dependent properties were not affected by pressure treatment.     

Microstructural and electrochemical properties of vertically aligned few layered graphene (FLG) nanoflakes and their application in methanol oxidation

Vertically aligned few layered graphene (FLG) nanoflakes were synthesised on silicon substrates by microwave plasma enhanced chemical vapour deposition (MPECVD) method. Transmission electron microscopy (TEM) shows that the structures have highly graphitized terminal planes of 1–3 layers of graphene. Raman spectroscopy revealed a narrow G band with a FWHM of ∼23 cm⁻¹ accompanied by a strong G′ (2D) band, with a FWHM of ∼43 cm⁻¹ and an I_G/I_G′ ratio of 1, which are all the characteristics of highly crystallized few layered graphene. The FLG electrodes demonstrate fast electron transfer (ET) kinetics for Fe(CN)₆^3−/4− redox system with an electron transfer rate, ΔE_p, of 60 mV. Platinum (Pt) nanoparticles of ∼6 nm diameter were deposited on as grown FLGs using magnetron DC sputtering for methanol oxidation studies. When used as electrodes for methanol oxidation, a mass specific peak current density of ∼62 mA mg⁻¹ cm⁻² of Pt is obtained with a high resistance to carbon monoxide (CO) poisoning as evident by a high value of 2.2 for the ratio of forward to backward anodic peak currents (I_f/I_b).     

Is randomisation necessary for measuring defocus curves in pre-presbyopes?

PURPOSE: Defocus curves are used to evaluate the subjective range of clear vision of presbyopic corrections such as in eyes implanted with accommodating intraocular lenses (IOLs). This study determines whether letter sequences and/or lens presentation order ought to be randomised when measuring defocus curves. METHODS: Defocus curves (range +2.00DS to -2.00DS) were measured on 18 pre-presbyopic subjects (mean age 24.1+/-4.2 years) for six combinations of sequential or randomised positive or negative lens progression and non-randomised or randomised letter sequences. The letters were presented on a computerised logMAR chart at 6m. RESULTS: Overall there was a statistically significant difference between the six combinations (ANOVA, p<0.05) attributable to the combination of non-randomised letters with non-randomised lens progression from negative to positive defocus (p<0.01). There was no statistically significant difference in defocus curve measurements if both letters and lens order were randomised compared to if only one of these variables was randomised (p>0.05). Non-randomised letters, with a sequential lens progression from negative to positive, was significantly different to all other combinations when compared individually (Student's T-test, p<0.003 on all comparisons), and was confirmed as the sole source of the overall significant difference. There was no statistically significant difference if both lens presentation order and letter sequences were randomised compared to if only one or the other of these variables was randomised. CONCLUSION: Non-randomised letters and non-randomised lens progression on their own did not affect the subjective amplitude of accommodation as measured by defocus curves, although their combination should be avoided.     

Structural and electrical properties of thermally evaporated 1,4-Bis-(2-hydroxyethylamino)-9,10-anthraquinone films

Nowadays applications of organic materials as the active element in microelectronic devices is broadly investigated. In the present paper, 1,4-Bis-(2-hydroxyethylamino)-9,10-anthraquinone compound has been synthesized. The films of this compound has been deposited by thermal evaporation technique on to the glass substrates which are kept at different temperatures in vacuum of ～1.33 × 10^?3 Pa. Scanning electron microscope (SEM) shows that the films are polycrystalline in nature. Wire like crystal of width 0.204 μm is observed at higher substrate temperature (333 K). The conduction in these films is ohmic in nature. The electrical conductivity and carrier concentration of these films increases with increase in substrate temperature as well as absolute temperature of the films. The analysis of optical absorption measurements on the films indicates that the optical band gap lies in the range 1.48–1.55 eV.     

Mathematical modeling of flux consumption during twin-wire welding

Mathematical models for flux consumption during twin-wire welding with direct current electrode positive and direct current electrode negative have been presented. The models illustrate the flux consumption in the form of a function relation between different process parameters. The present work is the result of a large number of experimental observations, modelling, and subsequent validation. The accuracy and predictability along with the use of shop-floor controllable parameters as model inputs make the proposed models useful for industrial application. The effects of process parameters have been further analyzed. The analysis revels that current, voltage, wire diameters and polarity are the major factors influencing the flux consumption during the twin wire welding, while welding speed and contact-tube-to-work-piece-distance are found to be significant with electrode negative. One of the important observations during the present investigation is regarding influence of dissimilar wire diameters at the lead and trail wires on the flux consumption. Mathematical analysis of magnetic field generated in the vicinity of the arc, particularly with dissimilar diameter, affects the arc deflection and affects the flux consumption.     

Effect of transverse shear and rotatory inertia on the forced axisymmetric response of linearly tapered circular plates

The forced axisymmetric response of linearly tapered circular plates, based on the shear theory is analyzed by the eigenfunction method. Clamped and simply supported plates subjected to constant and half-sine pulse loads, uniformly distributed over a symmetric portion of the plate, are solved as example problems. Numerical results computed for transverse deflection and radial stress of the plate are compared with the corresponding results of classical theory. Results obtained for a plate of constant thickness, as a particular case, are compared with closed form solutions and a very good agreement is found.