Influence of β-carotene-rich vegetables on the bioaccessibility of zinc and iron from food grains

Widespread deficiencies of iron and zinc, commonly found in populations dependent on plant foods, necessitate food-based strategies to maximise their bioavailability from plant foods. In this study, β-carotene-rich vegetables were evaluated for their effects on the bioaccessibility of iron and zinc from cereals and pulses by employing a simulated gastrointestinal digestion procedure involving equilibrium dialysis. Addition of carrot or amaranth (2.5 g and 5 g per 10 g of grain) significantly enhanced the bioaccessibility of iron and zinc from the food grains, the percent increase being 13.8–86.2 in the case of carrot and 11–193% in the case of amaranth. Pure β-carotene added at an equivalent level also enhanced the bioaccessibility of iron (19.6–102% increase) and zinc (16.5–118.0% increase) from the cereals examined. This is the first report on the beneficial influence of β-carotene on iron and zinc bioaccessibilities.     

Growth of aligned ZnO nanorod arrays from an aqueous solution: effect of additives and substrates

We report a simple, versatile, low cost fabrication technique for synthesizing nanorod arrays whose architecture is suited for many applications spanning the nanometer to micrometer range. Specifically, we have covered the range of nanorod diameter from 50 to 1200 nm. From a detailed study of the growth parameters involved in the synthesis of the ZnO nanorod arrays from an aqueous solution, we report, in particular, the effects of varying the capping agent, substrate and substrate-seeding. We find that seeding the substrate and selecting the appropriate capping agent play the most crucial roles in the alignment of nanorod arrays. Our study on the use of different precursor materials and varied substrates for the growth of ZnO nanorod arrays should lead to an enhanced understanding of the controllable growth of ZnO crystals and nanostructures.     

Numerical investigation of MHD convective free stream nanofluid flow influenced by radiation and chemical reaction over stretching cylinder

Chemically reacting magnetohydrodynamic radiative flow of convective free stream nanofluid through a stretching cylinder using Buongiorno's model is discussed. The behavior of Brownian motion and thermophoresis is also appropriate. By adopting the similarity transformation, the partial differential equation is diminished into a first-order ordinary differential equation (ODE). Since transformed equations are highly nonlinear these ODEs are solved by using mathematical simulation. The shooting procedure has been adopted to resolve converted equations along the attendant Runge–Kutta–Fehlberg technique. The reason behind the present work is to research the effects of different parameters of fluid, namely, magnetic parameter, free stream velocity, Brownian motion, thermophoresis, chemical reaction, heat radiation, Lewis number on nanoparticle concentration, temperature, and velocity distribution. The impact of significantly participating parameters on velocity, concentration, and temperature distribution is distinguished with appropriate physical significance. The convergence of solutions for temperature, velocity, and concentration profiles is studied carefully. The measured challenges of nanofluids are scale-up capacity, increase in nanofluid viscosity, nanoparticle dispersion, and nanofluid cost. It is observed that nanoparticle temperature rises for more value of Brownian motion parameter while it declines for higher Lewis number. The current study in the cylindrical region is related to novel free stream flow in the presence of chemical reactions along with convective conditions which find applications in electronic systems like microprocessors and in a wide variety of industries and in the field of biotechnology. The current research helps control the transport phenomena, helping production companies to find the quality of the desired product.     

Polypropylene–nano‐silica nanocomposite foams: mechanisms underlying foamability,and foam microstructure,crystallinity and mechanical properties

We investigate the production and characterization of foams prepared from polypropylene (PP) as well as PP–silica nanocomposites containing different loadings of nano‐silica. This study was carried out to investigate the mechanisms underlying the production of foams with a regular cell structure through the use of nano‐scale fillers. Foaming was carried out in batch mode using an autoclave with CO₂ as the physical blowing agent; high pressures of the order of 14 MPa were achieved through a combination of active pressurization and the use of high foaming temperatures. The resulting PP nanocomposite foams were characterized in detail to quantify the effect of the nano‐silica loading on the foam density and mechanical, morphological and thermal properties. The addition of nano‐silica in PP resulted in the improvement of foam quality – as assessed from the well‐defined and regular cell structures with absence of cell coalescence – as well as an increase in expansion ratio and decrease in foam density. Careful analyses of trends in cell size, cell density and expansion ratio of the foams were correlated with measurements of melt rheology and nano‐filler morphology of the unfoamed specimens in order to identify subtle details regarding the role of silica nanoparticles in improving foam quality. © 2019 Society of Chemical Industry     

Study on thermal,mechanical and morphological properties of recycled poly(vinyl chloride)/fly ash composites

The present study deals with the development of composite materials utilizing recycled poly(vinyl chloride) (r‐PVC) recovered from waste electrical and electronic materials and waste fly ash obtained from thermal power plants. The effect of the incorporation of fly ash on the mechanical, thermal and morphological properties of the r‐PVC matrix was studied. The primary characterization of r‐PVC and fly ash was done employing FTIR, EDX, particle size analysis and XRD analysis. Subsequently, fly ash with a particle size of approximately 9.29 μm was incorporated within the r‐PVC matrix. Composite sheets were prepared using a melt blending process followed by compression moulding. The mechanical test revealed an increase in the tensile strength and elongation at break of the r‐PVC/fly ash composite up to 30 wt% loading of fly ash beyond which there was a decrease in the tensile strength. The impact strength, however, decreased with increasing fly ash content in the r‐PVC matrix. The morphological properties of the composites showed a good distribution of the filler within the recycled matrix. The thermal properties of r‐PVC also improved with the incorporation of fly ash which was revealed from DSC and TGA studies. The water absorption test showed an increase in water uptake with the addition of fly ash in the r‐PVC matrix. © 2020 Society of Chemical Industry     

Modeling of Ascending/Descending Velocity of Metal Droplet Emulsified in Pb-Salt System

Metal–slag emulsion is an important process to enhance the reaction rate between the two phases; thus, it improves the heat and mass transfer of the process significantly. Various experimental studies have been carried out, and some system specific relations have been proposed by various investigators. A unified, theoretical study is lacking to model this complex phenomenon. Therefore, two simple models based on fundamental laws for metal droplet velocity (both ascending and descending) and bubble velocity, as well as its position at any instant of time, have been proposed. Analytical solutions have been obtained for the developed equations. Analytical solutions have been verified for the droplet velocity, traveling time, and size distribution in slag phase by performing high-temperature experiments in a Pb-salt system and comparing the obtained data with theory. The proposed model has also been verified with published experimental data for various liquid systems with a wide range of physical properties. A good agreement has been found between the analytical solution and the experimental and published data in all cases.     

An eco-friendly approach for toughening of polylactic acid from itaconic acid based elastomer

Sustainable and biocompatible novel lactic acid based bioelastomer (LBPE) was synthesized by polycondensation process which has been confirmed by FTIR and ¹H NMR. Owing to the resemblances in the lactate structures of polylactic acid (PLA) and LBPE, the synthesized LBPE bioelastomers can act as an excellent PLA toughener in presence of free radical initiator dicumyl peroxide (DCP). The mechanical, morphological and thermal were investigated. Chemical crosslinks endow the LBPE with relatively high elasticity and environmental stability which ultimately enhances the mechanical properties of PLA matrix.     

Electrosynthesis of polyaniline-based composite films and their electrochemical activity

Herein, we report the synthesis of organic–inorganic hybrids of polyaniline-rGO-ZnO (PRZ) ternary composite materials for a potential application in dye-sensitized solar cell (DSSC). A facile all-electrochemical method was adopted for the deposition of PRZ films on FTO-coated glass substrate. The PRZ hybrid assembly was subsequently characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry, and photoelectrochemical measurements. Further, the morphological and elemental composition features of PRZ were monitored by field emission SEM and EDX, respectively. Electrochemical impedance spectra suggest that the charge–transfer resistance for the ternary composite is distinctly decreased. The maximum conversion efficiency of DSSC with PRZ counter electrode reaches 2.84%, which is higher than that of polyaniline-reduced graphene oxide (rGO) counter electrode. This ternary composite (PRZ) with organic–inorganic hybrid architecture showing an enhanced photoelectrochemical activity might be exploited in future as a promising material for application in next-generation solar devices.     

Complex Perovskite system Dy0.5-xBaxSr0.5Co0.80Fe0.20O3-δ: As cathode for IT-SOFCs

The present work is intended to study mixed conductivity of complex perovskite oxide of chemical formula Dy_0.5-xBa_xSr_0.5Co_0.8Fe_0.2O_3-δ (DBSCF-x) (0 ≤ x ≤ 0.07) to check its suitability as cathode for intermediate temperature solid oxide fuel cell (IT-SOFCs). Low-temperature sol-gel combustion route has been used to prepare DBSCF-x systems. Structures are confirmed by X-ray diffraction (XRD), exhibit single-phase perovskite structures with orthorhombic symmetry (space group Pbnm) for all compositions. Thermogravimetry (TG) results indicate lattice oxygen loss in Ba-doped DBSCF system by heat treatment in temperature interval 50-850°C, which is enhanced in N₂ atmosphere then air; in contrast to that lattice oxygen, gain is observed for DBSCF-0 system. Temperature profile of DC conductivity exhibits metallic behavior of DBSCF-x system; however, the DBSCF-0 system shows semiconductor-to-metal transition at temperature around 450°C. DBSCF-0.03 system displays maximum electronic conductivity. Electrochemical performance of electrodes is studied in three-layer symmetrical cell configuration DBSCF-x/Ce_0.85Sm_0.15O_2-δ/DBSCF-x by complex impedance spectroscopy (CIS). Impedance diagram reveals the presence of three processes mainly associated with (a) diffusion of oxide ions/oxygen intermediates through electrode/electrolyte interface, (b) atomic oxygen diffusion within the electrode, and (c) oxide ion diffusion in the crystal lattice. ASR of the DBSCF-0.05 system is found 2.21 ohm cm² at 700°C, which is lowest amongst all studied compositions. Results show that it is possible to modify the electrochemical properties of the DBSCF-x system by changing the composition, but much more work even including optimization of layer thickness and microstructure will be needed to reduce the ASR to the level of the state-of-art-electrodes and thereby better utilize the potential of the DBSCF-x system.     

Mechanical Behavior of Castor-Oil-Based Advanced Polyurethane Functionalized with Glycidol and Siloxanes

Castor-oil-based polyurethane (PU), epoxy (glycidol) terminated polyurethane (EPU), and hydroxy terminated poly (dimethyl siloxane) (HTPDMS) modified EPU (EPDMS) were synthesized. The PU and EPU were synthesized with polyol:diisocyanate and polyol:diisocyanate:glycidol ratio of 1:1.2 and 1:3:3, respectively, whereas EPDMS was prepared by the incorporation of 5 wt.%, 10 wt.%, 20 wt.%, and 30 wt.% of HTPDMS into the EPU. The structural modification of EPDMS was confirmed by solid-state CP/MAS ¹³C and ²⁹Si NMR spectroscopy. The results of a tensile test revealed that the EPDMS with 10 wt.% loading of HTPDMS (EPDMS10) exhibited considerable enhancement in the tensile strength and modulus. The scanning electron microscope analysis was performed to understand the increased phase heterogeneity of the samples.