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Present investigation is concerned with mixed convection flow of Williamson nanoliquid over an unsteady slandering stretching sheet. Aspects of non-linear thermal radiation, Brownian diffusion and thermophoresis effects are addressed. Non-linear stretching surface of varying thickness induce the flow. Novel features of combined zero mass flux and convective conditions are accounted. Use of appropriate transformations results into the non-linear ODEs. Computations for the convergent solutions are provided. Graphs are designed for interpretations to quantities. Nusselt number and surface drag are computationally inspected. Our computed results indicate that attributes of nanoparticles and non-linear thermal radiation enhance the temperature distribution.

Due to porous structure, larger specific area, and potential to functionalize further, metal–organic frameworks (MOFs) are gaining attention in various fields, including electrochemical sensing of various analytes. MOFs are known to have excellent electrochemical activity because they mainly constitute a rich metallic center, possess huge specific area, and have multiple valence states. However, electrocatalytic activities of MOFs are greatly reduced due to their poor electronic conductivity for which high conductivity species are incorporated into the MOFs. In the present work, Co-based MOF (ZIF-67) was used as a porous matrix to encapsulate silver nanoparticles (Ag NPs) and on the surface of ZIF-67 multi-walled carbon nanotubes (MWCNTs) were decorated to obtain Ag@ZIF-67/MWCNT nanocomposite for the non-enzymatic electrochemical detection of glucose. The surface morphology of the synthesized nanocomposite was investigated by scanning electron microscopy, while crystallographic characterization was performed by X-ray powder diffraction. Cyclic voltammetry and chronoamperometry techniques were used to for the electrochemical monitoring of glucose. The electrochemical results demonstrated that Ag@ZIF-67/MWCNT showed an improved catalytic activity towards glucose in the concentration range of 33 μM to 400 μM with a low detection limit of 0.49 μM (S/N = 3), and reaction sensitivity of 13.014 μA μM−1 cm−2 as well as good selectivity in presence of ascorbic acid and uric acid.

Poly ( l -lacticacid) (PLLA) is an FDA approved material for bone tissue engineering but its inherent brittleness and low melting ability are major challenges for its large-scale commercial applications. This challenge can be overcome by making its blends. This study reports blends of PLLA with a relatively new class of polymer i.e. cyclic olefinic copolymer and their miscibility, thermal behavior, morphology, crystallinity, degradability, and excellent biocompatibility is evaluated. Blends were prepared by taking 5–30 weight percent COC with PLLA matrix using solvent casting method. Scanning electron microscopy (SEM) images revealed that PLLA/COC form miscible blends up to 5–20 wt% of COC. FTIR, XRD, and differential scanning calorimetry (DSC) data showed that addition of COC to PLLA resulted in decrease in crystallinity along with formation of new α′-crystalline phase which coexists with inherent α-phase of PLLA in the blends. The transformation of α′-form is due to the presence of Van der Waals forces of interactions of the polymer chain moieties between PLLA and COC. Interestingly, PLLA/COC blends exhibited superior mechanical properties in relation to the pure PLLA. Compressive modulus values for PLLA/COC 10wt% increased 117% as compared to pure PLLA. PLLA/COC blends at 10 wt% have maximum ultimate tensile strength, modulus, and toughness ~ 123%, 67.8% and, 18.87% respectively. PLLA/COC blends showed increased swelling and degradation results as compared to PLLA. PLLA/COC blends exhibited excellent cytocompatibility over PLLA with preosteoblast (MC3T3-E1) and bone marrow stem cells (BMSc) cell lines suggesting possible candidate for Bone Tissue Engineering.

The research encompasses on a comparative study of biodegradable membranes based on poly(vinyl alcohol) (PVA), starch (St), graphene oxide (GO) and reduced graphene oxide (rGO) for food packaging application. Four different concentrations, i.e., 10, 20, 30 and 40 mg, of GO and rGO were incorporated in membranes using in situ and ex situ reduction technique. The aim was to enhance the antibacterial and mechanical properties of PVA/St membranes. PVA/St membranes having 20 mg of in situ reduced graphene oxide (PVA/St/IrGO20) exhibited an exceptional tensile strength of 22.719 MPa and outstanding antibacterial activity, i.e., 38.89 ± 0.23 mm and 37.52 ± 0.41 mm, against Escherichia coli and Methicillin-resistant Staphylococcus aureus, respectively. The membranes were also analyzed by scanning electron microscopy (SEM), X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). SEM results revealed the dense morphology for all membranes. FTIR results displayed the successful synthesis of GO, rGO and nanocomposite membranes. The TGA showed that IrGO membranes were more stable as compared to neat and graphene oxide membranes. Moreover, the membranes degraded completely after being buried in the soil. Among all the synthesized membranes, PVA/St/IrGO20 and PVA/St/XrGO10 (PVA/St containing 10 mg ex situ reduced GO) exhibited excellent barrier against water vapor and oxygen transmission. Therefore, they prolonged the shelf life of packed gooseberries as compared to all formulated membranes.

Bone whitlockite (WH) exists in the collagen matrix along with hydroxyapatite (HA) and plays a vital role during earlier stages of bone development. It is present in short-range order and is difficult to identify in the bone, as compared to HA mineral, that covers 80% of the bone inorganic phase. It has the same structural analogy with β-TCP, but detailed structural and crystallographic analyses of bone have shown that β-tricalcium phosphate (β-TCP) is merely a synthetic analog of bone whitlockite, having the same crystalline structure but different chemically. WH contains magnesium at Ca(IV), Ca(V) positions, and HPO42− on a threefold axis in a rhombohedral crystal lattice. Its biocompatibility, functionality, negative surface charge, mechanical strength, and stability in physiological solvents make it an ideal bone substitute as compared to hydroxyapatite (HA) and β-TCP. It has magnesium as a major component that has a strong affinity with integrin protein. Integrin protein plays a vital role in bone tissue integration. It is bioresorbable and biodegradable and the rate of degradation complements with regeneration. However, despite these excellent properties, this material has always been overshadowed by other calcium phosphates (CaPs), because it is difficult to synthesize. In this review article, we present a comprehensive study on the difference in the crystalline structure of bone whitlockite and β-TCP, its presence in the natural system, and conditions under which its nucleation occurs in native bone and at lab scale. Furthermore, the reaction conditions that favor homogenous precipitation of synthetic WH and the role of magnesium in the stabilization of different CaPs to obtain pure WH phase are also discussed. Finally, the applications of WH in biomedical and for heavy metal adsorption are summarized.

This analysis explores stagnation point in Jeffery liquid flow over a stretchable cylinder. Heat and mass transfer are investigated through Cattaneo–Christov model with double stratification, heat source and thermal relaxation. Moreover, the flow of liquid is caused by stretchable cylinder. Cylindrical coordinates are used for mathematical formulations. The acquired boundary layer problems for stretchable cylinder are dealt through homotopy analysis method. Results of variables appeared in governing equations are disclosed through graphs for flow, temperature, concentration and skin friction. The findings of the study show that higher values of ratio parameter and Deborah number in terms of relaxation time reduce magnitude of drag coefficient while reverse trend is noted for larger Deborah number in terms of retardation time and curvature parameter. Comparison of present work with previous published date is presented.

Peristalsis of carbon nanotubes (SWCNTs, MWCNTs) submerged in water through an inclined asymmetric channel is addressed in the current work. Such mechanism is disclosed in the presence of Hall effect, viscous dissipation, and Soret and Dufour effects. Convective heat transfer at the boundaries is incorporated by utilizing efficient thermal conductivity of nanoliquid. Low Reynolds number and long wavelength approximation are used for mathematical modeling. Resulting nonlinear set of equations is solved for pressure gradient, velocity, temperature and concentration. Impact of various variables on the axial velocity, pressure rise, pressure gradient, temperature, concentration, heat transport at boundaries and streamlines are discussed via their respective curves. Comparison between SWCNTs (single-wall carbon nanotubes) and MWCNTs (multiwall carbon nanotubes) is documented. Furthermore, submerging carbon nanotubes in water declines the velocity and temperature. In addition, heat transfer at the boundaries enhances by increasing volume fraction of carbon nanotubes. SWCNTs nanofluid shows higher velocity and concentration when compared with MWCNTs nanofluid. MWCNTs nanoliquid displays higher temperature than SWCNTs nanoliquid.

The structure-properties relationships of novel cyclic olefinic copolymer (COC)/poly(L-lactic acid) (PLLA) polymer blends are investigated by varying the PLLA content from 5–20 wt % in COC matrix, forming an immiscible blends at all concentrations. Despite immiscibility, COC favors the formation of α- crystal form of PLLA in the blends, contrary to the α’- crystal form in neat PLLA due to non-covalent interactions of the chain moieties as evident from x-ray diffraction, Fourier transform infrared spectrometer and differential scanning calorimetry. The COC/PLLA blends revealed tunable superior mechanical and barrier properties as compared to the neat counterparts. The tensile modulus, strength and toughness of COC/PLLA blends at 15 wt% are significantly enhanced ∼ 89 %, 103 % and one order of magnitude, respectively. Such reinforcement and super toughening mechanisms are pertaining to the effective dissipation of loads across the interfaces, enabling them to delay the crack growth by avoiding stress concentration sites. Likewise, the water vapor permeation (WVP) of the blends is reduced ∼ 4 times than neat COC.

This article investigates the effect of powder metallurgy processing parameters on multi-responses: mass density and hardness of Al2O3/Cu composite based on Taguchi method coupled with Grey relational analysis. Based on Taguchi’s L18 orthogonal array, the experimental trial runs were conducted with four controllable powder processing parameters: milling time, compaction pressure, sintering temperature and holding time. The Grey relational analysis (GRA) was performed to find the optimal powder processing condition with Grey relational grade (GRG) as a measure of performance index. Analysis of variance (ANOVA), 3D surface plots and contour plots were used to express the most influential parameter that affects mass density and hardness of Al2O3/Cu composite. Confirmation tests were conducted to make sure the validity of test results. The scanning electron microscope (SEM) images show the presence of Al2O3 particle in the composite. The Energy Dispersive X-Ray (EDX) spectrum indicates the presence of chemical elements: Cu, Al, O in the composite. The results show that the optimal powder metallurgy parameter combination is A2B3C3D1. The mean Grey relational coefficient (GRC) analysis shows that the mass density was more easily influenced by factors considered compare to hardness. The mean GRG result shows that the compaction pressure has the strongest correlation to responses. The result of 3D surface plots, contour plots and ANOVA indicate that the compaction pressure has most influential parameter that affect GRG. The % contribution of parameters shows that the % contribution of compaction pressure is significant (80.22%) compare to other main effects and interaction effects. The confirmation tests revealed that the performance characteristic of Al2O3/Cu composite was improved by GRA based Taguchi technique. The Monte Carlo simulated model summery show that based on Taguchi L18 Orthogonal Array design, one can easily find the reality of what will be happening in a process. Therefore, optimization of processes parameter could be simplified by using the Grey-based Taguchi method.

In this paper, we present a novel one-step, easy and cost-effective method for the synthesis of Ag-doped TiO2 sol and deposition of its compact thin films by spin coating technique. The effects of dopant quantity (0–5% by weight) on structural, morphological, optical and electrical properties of TiO2 thin films have been investigated and reported. The X-ray Diffraction (XRD) spectra revealed single anatase phase having no secondary phases. The scanning electron microscopy (SEM) showed pinholes-free/compact thin films composed of spherical nanoparticles where the particle size has been demonstrated to decrease with increasing Ag doping. The atomic force microscopy (AFM) confirmed smooth and compact TiO2 thin films, however, the surface roughness tends to grow with increasing the dopant quantity. The X-ray fluorescence spectroscopy (XRF) revealed the presence of Ag mass percentage in the relevant samples, which has been demonstrated to grow with increasing the amount of dopant. The UV–Vis spectroscopy concluded the bandgap reduction of pure anatase phase of TiO2 (3.38 eV) as the Ag doping reaches to its maximum value of 5% (3.18 eV). Spectroscopic Ellipsometry has been employed to determine the thickness of thin films which was found to be in the range of ~ 100 nm, while electrical properties have been measured through DC-Hall Effect technique. It was found that the conductivity of thin films improved from 5.74 × 10–2 to 2.72 × 10–1 Ω−1 cm−1 on glass while on FTO-coated glass substrates, a higher value of 1.51 × 104 Ω−1 cm−1 was achieved.

In this article, the hydrodynamic stability of the Couette flow of an electrically conducting fluid flowing in a parallel-plate channel with a normal magnetic field is investigated through a porous medium. The transport phenomena in the porous medium have been of enduring interest from the last few decades. The linear perturbation theory of hydrodynamic stability along with the presumption of low magnetic Reynolds number is applied to the governing equations to derive the governing magnetohydrodynamic stability equation. A Chebyshev collocation method is operated to numerically elucidate the magnetohydrodynamic stability equation. A linearized velocity solution for developing flow is used in the stability calculations. The numerically determined neutral stability results for the fully developed Couette flow are in excellent agreement with those of the analytical solution. The results presented here for Hartmann flow are believed to be more accurate owing to the more exact nature of the numerical solution.

The addressed work explains SWCNTs (Single walled carbon nanotubnes) and MWCNTs (Multi walled carbon nanotubnes) nanofluid flow under the influences of temperature dependent viscosity and mixed convection. Comparative study of SWCNTs and MWCNTs suspended in base liquid is presented. Further heat and mass transfer are addressed for nanofluid effected by radiation, heat generation/absorption and diffusion species. Mathematical development of problem is taken in cylindrical coordinates. System of highly nonlinear differential equations are constructed via appropriate transformations. The system of equations are tackled numerically by bvp4c MATLAB solver. The findings of the study show that larger volume fraction $$\left( \phi \right)$$ ϕ contributes to enhance the nanoliquid flow. The velocity by submerging MWCNTs is noted higher than SWCNTs. Furthermore, the relationship between the viscosity variable $$\left( \theta _{r}\right)$$ θ r and the temperature is such that the temperature near the surface decreases with increase in $$\left( \theta _{r}\right)$$ θ r , while at the same time the temperature away from the surface increases. Subsequently, higher temperature is observed in SWCNTs-liquid compared to the MWCNTs-liquid to the similar values of $$\left( \theta _{r}\right)$$ θ r . Further, heat transfer is an increasing function of varying viscosity variable $$\left( \theta _{r}\right)$$ θ r .

In this paper, we present a simple route to synthesize PBS/nHAP polymer nanocomposites and share our findings on the influence of nHAP (filler) on the PBS (matrix). The filler weight content was varied from 0.0 g to 0.10 g. These effects that were investigated were the structural, morphological, mechanical, wettability, and roughness parameters. The X-ray Diffraction (XRD) spectra revealed that PBS and nHAP produced their separate phases. The Scanning Electron Microscopy (SEM) results display pores in the Neat PBS while pores are filled in the PBS/nHAP polymer nanocomposites. Further increase in the filler content revealed that agglomeration began to occur, and it permeated out of the pores and onto the surface imparting brittleness to the composite. The mechanical results confirm the increase in tensile strength up to a certain point of nHAP-5. The wettability studies prove that by increasing the filler weight content, the hydrophobic nature converts to a moderate hydrophilic nature. The roughness studies revealed the roughness values of the PBS/nHAP composites to be higher than that of Neat PBS.

Mid-wave and long-wave infrared (MWIR and LWIR) detection play vital roles in applications that include health care, remote sensing, and thermal imaging. However, detectors in this spectral range often require complex fabrication processes and/or cryogenic cooling and are typically expensive, which motivates the development of simple alternatives. Here, we demonstrate broadband (0.43-10 μm) room-temperature photodetection based on copper tetracyanoquinodimethane (CuTCNQ), a metal-organic semiconductor, synthesized via a facile wet-chemical reaction. The CuTCNQ crystals are simply drop-cast onto interdigitated electrode chips to realize photoconductors. The photoresponse is governed by a combination of interband (0.43-3.35 μm) and midgap (3.35-10 μm) transitions. The devices show response times (∼365 μs) that would be sufficient for many infrared applications (e.g., video rate imaging), with a frequency cutoff point of 1 kHz.

Nanofluids are the diluted interruptions of nano-sized particles in base fluid such as oil, ethylene glycol, water etc. Nanofluids have wide applications in industries because of their enhanced thermal properties. In present article, the stability analysis of MHD (Magneto-hydro-dynamic) Poiseuille flow of thermocapillary liquid layers of shear thinning nanofluids with oxide nanoparticles in base fluid (water) by imposing transverse magnetic field are studied. The oxide nanoparticles of Aluminum oxide (Al2O3), copper oxide (CuO), graphene oxide (GO), Iron oxide (Fe3O4), and titanium oxide (TiO2) are used. Numerical method used in current work is “cheybeshev collocation method”. To finding the eigenvalues from generalized Orr-sommerfeld equations, an algorithm named “QZ (Qualitat and Zuverlassigkeit)” used. The stability of different oxide nanoparticles based water nanofluids are compared and discussed through graphs. It has been found that Iron oxide based water nanofluid flow has more destabilizing effect and graphene oxide based water nanofluid flow has more stabilizing effect as compared to other oxide nanoparticles.

In this article, the characteristics of physical model steady axisymmetric flow of cross-fluid over a stretching sheet are explored numerically. Furthermore, steady flow of nanofluid is expressed by means of Buongiorno’s model for nanoparticles. Moreover, the features of thermal radiation and chemical reaction processes with partial velocity slip condition are adopted here. Nonlinear PDEs are converted to ODEs using suitable transformation variables. The reduced systems of ODEs are resolved using an effective bvp4c scheme implemented. Numerical computation for physical parameters such as skin friction, Nusselt and Sherwood numbers are also examined. Magnetic field plays a vital role in controlling the flow of fluid and has the tendency to enhance the thermal boundary layer and concentration. Similarly, skin friction, Nusselt and Sherwood numbers depreciate by improving the values of velocity slip parameter, magnetic parameter, magnetic parameter, thermophoresis parameter in shear thickening fluids.

The present research work elucidates the photocatalytic effect of titania on liquid crystal based sensor used to detect sodium arsenate in water. The titania nanoparticles with an average size of 18-20 nm were synthesized by hydrothermal method and calcined up to 500 °C to obtain pure anatase phase. The catalytic activity of titania nanoparticles was enhanced by surface modification with (3-aminopropyl) trimethoxysilane. The sensing experiment was performed under visible light irradiation while keeping the concentration of substrate, analyte, the thickness of the liquid crystal layer, temperature and pH values constant. In addition, span 80 (a non-ionic surfactant) was used to obtain homeotropic alignment of liquid crystals. The TiO₂ nanoparticles gave dark to bright texture within 53 min while the functionalized titania responded in less than 25 min under similar sensing condition. The detection results showed that the functionalized titania nanoparticles possess greater photocatalytic activity under visible light and enhanced the sensing response than unfunctionalized titania nanoparticles.

The present work focused here is a mixed convective MHD flow of cross fluid in the presence of heat generation/absorption and variable thermal conductivity over a bidirectional stretchable sheet. To elaborate the mechanism of heat transfer is analyzed in view of non-Fourier heat flux based upon Cattaneo–Christov theory. The influence of a simple isothermal model of homogeneous–heterogeneous reactions is further used for solute concentration. As a result, the relevant Buongiorno fluid model is utilized in mathematical modeling and then it is simplified through lubrication technique. By using appropriate transformations, the raised PDEs initially converted to ODEs. Convergent solutions of ODEs are obtained by the implementation of the numerical procedure bvp4c technique. However, the velocity, temperature and concentration profiles have been sketched by distinct physical flow parameter. Drag coefficients and heat transport are also computed numerically. Our results reveal that temperature profile has an inverse relation between the relaxation parameter and variable thermal conductivity.

In the present work, an attempt has been made to develop immediate release coated tablets of Ritonavir by hot met extrusion method using 16 station rotary tablet punching machine. The blend of all the formulations showed good flow properties such as bulk density, tapped density. The prepared IR coated tablets of ritonavir shown good post compression parameters. They passed all the quality control evaluation parameters as per USP limits. Among all the formulations, F5 formulation showed maximum % drug release i.e., 99 % in 120 mins hence it is considered as optimized formulation. The optimized formulation was compared to innovator tablets. Keywords: Ritonavir, HPMC, Ethyl cellulose, Copovidone immediate release tablets.

The current industrial revolution signifies the high-value of biocatalysis engineering. Over the past decade, multiple micro- and nanostructured materials have been attempted for immobilization of enzymes to improve their catalytic properties. Conventional immobilization strategies result in improved stability, while insolubilized enzymes generally lost their activity compared to free counterparts. Recently, a new generation organic-inorganic hybrid nanoflowers with unique properties have received great attention as a novel and incentive immobilization approach owing to their simple fabrication, high biocatalytic efficiency, and enzyme stabilizing capability. The hybrid nanoflowers biocatalytic system implicates metal ions and biomolecules (enzymes). In contrast to free or conventionally immobilized enzymes, single enzyme or multi enzyme-incorporated flowers-like hybrid nanoconstructs demonstrated elevated catalytic activities and stabilities over a very broader range of experimental conditions, i.e., pHs, temperatures and salt concentration. This review discusses the recent developments in the fabrication strategies to diversifying nanoflowers, types, characteristics, and applications of organic-inorganic hybrid nanoflowers as a host platform to engineer different kinds of enzymes with requisite functionalities for biocatalysis applications in different sectors of the modern world. Based on experimental and theoretical literature data, the review is wrapped up with concluding remarks and an outlook in terms of upcoming challenges and prospects for their scale-up applications.

In this work the electrochemical oxidation of methanol is studied on NiO based MOFs and its composites with reduced graphene oxides. NiO-MOF and its composites were prepared through hydrothermal method. The as-prepared materials were characterized by SEM, EDX, XRD, FTIR and Raman IR for their morphological and structural properties. The activity of prepared catalyst for oxidation of methanol was tested via cyclic voltammetry (CV) in an alkaline media on glassy carbon electrode. The electrochemical performance shows the effect of rGO concentration on methanol oxidation. The electro oxidation catalyzed by NiO-MOF and NiO-MOF/rGO composites exhibits a magnificent peak current density of 275.85 mA/cm2 at 0.8 V potential with a scan rate 50 mV/s making them a potential candidate for electrocatalysis.

Controlling the kinetics of CuTCNQ (TCNQ = 7,7,8,8-tetracyanoquinodimethane) crystallization has been a major challenge, as CuTCNQ crystallizing on Cu foil during synthesis in conventional solvents such as acetonitrile simultaneously dissolves into the reaction medium. In this work, we address this challenge by using water as a universal co-solvent to control the kinetics of crystallization and growth of phase I CuTCNQ. Water increases the dielectric constant of the reaction medium, shifting the equilibrium toward CuTCNQ crystallization while concomitantly decreasing the dissolution of CuTCNQ. This allows more CuTCNQ to be controllably crystallized on the surface of the Cu foil. Different sizes of CuTCNQ crystals formed on Cu foil under different water/DMSO admixtures influence the solvophilicity of these materials. This has important implications in their catalytic performance, as water-induced changes in the surface properties of these materials can make them highly hydrophilic, which allows the CuTCNQ to act as an efficient catalyst as it brings the aqueous reactants in close vicinity of the catalyst. Evidently, the CuTCNQ synthesized in 30% (v/v) water/DMSO showed superior catalytic activity for ferricyanide reduction with 95% completion achieved within a few minutes in contrast to CuTCNQ synthesized in DMSO that took over 92 min.

The aim of the current study is to disclose the results of shape factor analysis of the flow of a hybrid nanofluid over a curved sheet. The flow is caused by a stretchable curved sheet. Mathematical modeling and analyses have been performed in the presence of curvature, melting heat and heterogeneous-homogeneous reactions. Autocatalysis and the coefficients of the reactant are dealt with in a similar manner. The physical properties of the fluid, including the fluid velocity, the heat and mass transfer properties, the skin friction and the Nusselt number have been acquired and analyzed under the influences of the dimensionless curvature, melting and heterogeneous–homogeneous reaction variables. Boundary layer approximations are used in the mathematical formulation. Suitable transformations have been used to transform differential equations into nonlinear ordinary differential equations. The resulting nonlinear system of equations has been analyzed via the matlab bvp4c solver. Comparisons of nanoliquids with the hybrid nanoliquid are presented through graphs and tables. The results of this analysis show that the skin friction and the heat transfer rate in the hybrid nanofluid are seen more prominently than those of the nanofluid for larger values of the curvature parameter [Formula: see text].

Global warming is attributed to CO2 emissions which are responsible for climate change. Various industries such as cement manufacturing plants, power plants, petrochemical industries, iron, and steel are the major contributors of CO2 emissions. Carbon capture and storage has been considered as an essential technology to reduce CO2 emissions into the atmosphere. Conventionally, amine-based solvents are used for the CO2 capture in the industry. These conventional processes suffer from numerous problems such as high vapor pressure, corrosion, degradation of the solvents, and requirement of high regeneration energy. Ionic liquids (ILs) are widely accepted as the solvents of next generation having capability to replace the amine solvents for the CO2 absorption. The non-volatility, superior thermal stability, non-corrosiveness, and low regeneration energy make them ideal for future perspective. However, ionic liquids have significantly lower CO2 solubility as compared to conventional solvents and requires complex purification step which adds to its cost. Deep eutectic solvents (DESs) are believed to be IL-analogues having similar property and have shown ability for CO2 absorption. The potential application of ionic liquids and deep eutectic solvents as alternatives to amine solvents has been discussed in this chapter.

This work presents the preparation of an efficient and sensitive glucose sensor for the detection of glucose in an alkaline media. The glucose sensor is composed of a metal organic framework (MOF) composite comprising Ag@TiO2 nanoparticles. The hybrid of Ag@TiO2 encapsulated in ZIF-67 was synthesized by the solvothermal method and applied onto a glassy carbon electrode (GCE) for the non-enzymatic sensing of glucose. The porosity of ZIF-67 was favorable for the unhindered diffusion and entrapment of glucose and its cavities served as reaction vessels. The electrochemical behavior of Ag@TiO2@ZIF-67 showed amplified results when compared with that of Ag@TiO2 and ZIF-67. Cyclic tests toward the oxidation of glucose has demonstrated excellent stability of a MOF-based hybrid sensor. The sensor based on Ag@TiO2@ZIF-67 showed high sensitivity of 0.788 μAμM−1cm−2 with a linear concentration range of 48 μM−1 mM and a response time of 5 s with an excellent detection limit of 0.99 μM (S/N = 3).

In this work, the reaction kinetics of sequential deposition technique were optimized to produce large area (~ 1 cm2), uniform and pinhole free hybrid CH3NH3PbI3 perovskite (MAPbI) thin films in ambient air; at room temperature and a relatively high humidity level of ~ 50%. The MAPbI thin films were grown upon a thin passivation layer of CH3NH3I (MAI) using conventional two step deposition scheme. The films were characterized using Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Electroimpedance Spectroscopy, Current–Voltage and DC-Hall effect measurements. The resultant MAPbI thin films demonstrated negligible amount of unreacted PbI2 because of the sandwich structure where PbI2 layer was embedded in-between two MAI layers. Thin films showed a decreased resistance (~ 14 MΩ), increased intrinsic charge carrier concentration (~ 9.3 × 1015 cm−3) and higher charge carrier mobilities (~ 195 cm2 V−1s−1). The decrease in resistance and increase in charge carrier mobilities were attributed to the reduced trap sites and grain boundaries in MAPbI thin film front face due to the MAI passivation layer. The increase in charge carrier density was a consequence of MAI passivation layer on the energy levels tuning of MAPbI. The MAPbI thin films also showed promising stability of above 70%; after 8 weeks of ambient air storage and without any encapsulation.

Micropiles are drilled and grouted piles having diameter between 100 to 250 mm. Due to its small diameter, it is suitable for low headroom and limited work area conditions. It can be installed without noise nuisance, without vibrations to surrounding soils and structures and without disruption to the production operations in industries which makes micropiles suitable for underpinning and seismic retrofitting of structures. It is necessary to therefore understand the behaviour of micropiles under different loading conditions. This work is on vertical and battered micropiles with different length/diameter ratio (L/D) subjected to vertical and lateral loading conditions. Batter angles had a significant influence on both the vertical and lateral load carrying capacity. The ultimate vertical load was found to increase upto a 30° batter. The ultimate lateral load was found to increase significantly with increasing L/D ratios upto an L/D ratio of 30 for vertical and 48 for battered piles, beyond which the increase was found to be not significant. In general, negative battered micropiles offered more lateral resistance than positive battered micropiles. The results of the study indicated that the ultimate load capacity and mode of failure of the micropiles are a function of the angle of batter, direction of batter and the L/D ratio for vertically and laterally loaded micropiles.

This study reports Darcy-Forchheimer flow of MHD Jeffrey nanofluid bounded by non-linear stretching sheet with variable thickness. Thermophoresis and Brownian motion are studied. Heat transfer is accounted with melting heat and heat absorption/generation. Optimal homotopy analysis method is utilized for the solutions development of non-linear ordinary differential system. Outcomes of parameters involved in equation are studied through graphs. Outcomes indicate that ratio parameter declines the velocity. Melting parameter enhances temperature and concentration. Nusselt number increases in the occurrence of thermophoresis Brownian motion

Two-dimensional (2D) graphene and its outstanding properties such as, enormous conductivities, mechanical strength, optical and electrical properties brought it one of the most studied materials for the production of energy using renewable resources. The composites of graphene with the same morphological materials such as layered transition metal oxides will be the most aspiring combination to boost their conducting, optoelectronic and mechanical properties. Furthermore, the transition metal chalcogenides materials attracted significant attention due to their atomically thin layers and enormous optical, conducting and electrical properties. The layered materials offer mostly atomically thin 2D plane to the charge carrier with superior conducting properties. The thickness at atomic level, band gap, spin orbit coupling electronic and optoelectronics properties of transition metal dichalcogenides makes them one of the promising entities in energy harvesting technologies. The review suggests some strategies to improve the transition metals-composites stability conducting properties to be tailored in various applications.

Green syntheses of nanoparticles using plant materials are of tremendous scope. Here we report advantageous green synthesis for silver nanoparticles (AgNPs) using aqueous-root extract of Jurinea dolomiaea and AgNO3. Color change of solution and UV-Vis absorption at 444 nm indicated the formation of AgNPs. XRD confirmed their face centered cubic structure (fcc) with average particle size of 24.58 nm. SEM analysis showed their spherical, cubic and triangular structures. FT-IR indicated the presence of functional groups of reducing and stabilizing phytochemicals. Methanol-root extract of J. dolomiaea revealed high flavonoid (445 mg RE/g) and phenolic contents (92 mg GAE/g). Methanol-extract showed high antioxidant potency (IC50 = 0.494 μg/mL), rationally due to its high phenolic and flavonoid contents. These AgNPs showed the highest and equal antimicrobial activities against Escherichia coli and Pseudomonas aeruginosa (Inhibition zone 11.0 mm) whereas, methanol-roots extract showed equal and intermediate activities (Inhibition zone 8.0 mm) against both pathogens but aqueous extract showed poor activities (Inhibition zone 6.0 mm) against these both pathogens. AgNPs are playing a major role in the field of nanotechnology and nanomedicine due to their antimicrobial and drug delivery efficacy as well as reasonable tolerance in human biology.

Present study deals with Darcy Forhheimer application to CNTs nanofluid flow due to a cylinder and flat sheet. Thermal conductivity of CNTs nanofluid is inspected under renovated Hamilton-Crosser and Xue models. The solute concentration is regulated through a simple isothermal model of homogeneous-heterogeneous reactions. Thermodynamics processes of reactant and autocatalyst analyze the impact of temperature phase changes like evaporation or convection. It is considered that the base fluid (water) is essentially composed of SWCNT-Water (base fluid with SWCNT) and MWCNT-Water (base fluid with MWCNT). The solution of the problem is obtained by using implicit finite difference method (Keller-Box). It is unconditionally convergent and the well-tested extensively validated method. Influence of physically involved parameters are illustrated through graphs. Darcy Forhheimer parameters decline the fluid flow. The fluid velocity and thermal boundary layer thickness in case of flat sheet is higher when compared with stretching cylinder. Interestingly reverse outcomes are preserved for concentration. Homogeneous reaction parameter and Schmidt number have opposite trend on nanoparticle concentration. Higher curvature parameter is accounted for drag coefficient and heat transfer at the cylinder. Renovated Hamilton-Crosser model have larger thermal conductivity when compared with Xue model. Comparison of current result with previous result is given. The outcomes are found in an excellent agreement. Keywords: Keller box method, CNTs (SWCNT and MWCNT), Stretching cylinder and flat sheet, Renovated Hamilton-Crosser model, Xue model, Darcy Forhheimer law

Bimetallic sulfides have particle rich surface due to which they possess novel electrical, optical and magnetic properties. Current research has undertaken the synthesis of Nickel and Manganese dithiocarbamate complexes and complexes were incorporated in bimetallic form by combine decomposition. Combined FTIR peaks confirmed the bimetallic complex formation of Nickel and Manganese. UV–Vis absorption spectra of C10H20NiN2S4 expressed peak at 290 nm and C10H20MnN2S4 expressed peak at 317 nm. Furthermore, The UV–Vis peak for bimetallic composites Ni3S2/MnS2 was obtained at 340 nm. SEM exhibited the cubic shaped crystal structure of NiS/MnS composites. SEM were performed with the results confirming the synthesis of crystalline bimetallic sulfides/composites Ni3S2 and MnS2. Composite was utilized to make thin film by PVD assisted technique and band gap was 1.69 eV. Hence, it is suggested that composites Ni3S2 and MnS2 reveals promising prospect in lithium-ion batteries, supercapacitors and as an anode or cathode material for future applications.

A simple, sensitive, selective and real time detection protocol was developed for Pb2+ ions in water using liquid crystals (LCs). In this method, NiFe2O4 nanoparticles were synthesized using chemical co-precipitation method. Crystallite size, morphological, functional groups and magnetization studies were confirmed using X-ray diffraction, Scanning Electron Microscopy, and Fourier transform infrared spectroscopy techniques, respectively. The nanoparticles were mono dispersed with average particle size of 20 ± 2 nm. The surfactant stabilized magnetic nanoparticles were incubated in liquid crystal based sensor system for the detection of Pb+2 ions. The bright to dark transition of LC was observed through optical microscope. When this system was further immersed with a solution containing Pb2+ ions, it caused homeotropic to planar orientation of LC. This interaction is attributed to the presence of abundant hydroxyl groups in such as M-OH, Fe-OH on the surface of spinel ferrites nanoparticles. These groups interact with metal ions at aqueous interface, causing disruption in LCs orientation giving bright texture. This sensor showed higher selectivity towards Pb2+ ions. The detection limit was estimated to be 100 ppb. The cheap and effective protocol reported here should make promising development of LC based sensor for lead ion detection. Keywords: Chemical co-precipitation method, Fourier transform infrared spectroscopy, Liquid crystals, Nanoparticles, Sensor, X-ray diffraction

Three-dimensional flow of carbon water nanofluid by nonlinear stretched sheet is studied. Nanofluid saturates the porous space. Heat transfer mechanism is examined via more suitable convective type condition and nonuniform heat generation/absorption. The solutal concentration is regulated by a simple isothermal model of homogeneous–heterogeneous reactions. The numerical solutions are obtained through shooting technique by Runge–Kutta method of order five. Both single and multiple walled carbon nanotubes as nanoparticles in the base fluid are considered. Graphical illustrations and tabulated values point out the impact of sundry variables. Both components of velocity show reverse effect for stretching rate ratio. The simulations predict that wall heat flux is inversely proportional to heat generation variable. However value of heat flux is predicted more in case of larger convecting heating strength and volume fraction of carbon nanotubes. Heat transfer coefficient is more in single walled carbon nanotubes (SWCNTs) than in multi walled carbon nanotubes (MWCNTs). Heterogeneous–homogeneous variables and Schmidt number have opposite behaviors on nanoparticle concentration distribution. Excellent agreement is shown through comparison of past and present results.

Comparative analysis for flow of CNTs nanofluids is discoursed in the presence of non-Darcy porous medium. The consequences of homogeneous/heterogeneous process and heat transfer through convection are employed. The flow induced is due to non-linear stretching sheet of variable thickness. The bottom of the variable thickness sheet is heated by convective processes from a heated fluid. The velocity, temperature and concentration functions are formulated for the stretched flow problem. Convergence control variables and square residual errors for series solutions are obtained through OHAM (Optimal Homotopy Analysis Method). Biot number corresponds to larger temperature distribution in case of MWCNT than SWCNT . Comparison of nanoparicles SWCNT and MWCNT for the CNTs nanofluid fluids is highlighted. Water and engine oil CNTs fluids have higher magnitude of Nusselt number when compared with kerosene oil CNT fluid. The heat transfer rate in the presence of MWCNT is higher than SWCNT . Comparison of present study with previous published data is made. The outcomes are found in favorable agreement.

Three-dimensional flow of carbon–water nanofluid due to slendering nonlinear stretching sheet with slip effects is covered in this study. Nanofluid saturates the porous space. We consider water based SWNT and MWCNT nanofluids in this study. Isothermal model of homogeneous–heterogeneous reactions regulates the concentration. The system of partial differential equations is converted into ordinary differential equations. The numerical solutions are obtained through bvp4c technique. Tabulated values and graphical illustrations are pointed out for the influence of sundry variables. Volume fraction corresponds to enhancing the flow behavior while slip variable shows decline in flow. The simulations show that wall heat flux is inversely proportional to slip effect. However value of heat flux is predicted more in case of larger values of variable thickness variable. Heat transfer performance of MCNT case is higher when compared with SWCNT. Homogeneous variable and Schmidt number have opposite behaviors on nanoparticle concentration distribution. Favorable agreement is shown through comparison of past and present results in limiting case.

Effect of the polymerization of aniline on graphene oxide (GO) surface on the thermal stability, electrical and optical properties of GO has been studied through its chemical functionalization with aniline and polyaniline. GO obtained through liquid ex-foliation of graphite flakes was further covalently coupled with aniline and PANI through imidation protocol in order to extend its piconjugation and to study its effect on opto-electronic properties. Band gap of pristine as well as chemically modified GO was calculated through UV-Vis spectroscopy. It was found that after functionalization, band gap of GO decreased from 3.82 eV to 2.87eV. Furthermore, the conductivity of GO increased from 96.04 S/cm to 139.87 S/cm after modifying with PANI. XRD, FTIR, TGA and elemental analysis data have supported the difference in the properties of modified GO with aniline and PANI. Finally, TGA analysis showed that the thermal stability of GO was enhanced up to 20% due to the addition of PANI.

We demonstrate room-temperature photodetectors at wavelengths from visible (450 nm, 532 nm) to near- (850 nm), short-wave (1550 nm), mid-wave $(4.5 \mu m)$ and long-wave $(8.35 \mu m)$ infrared. These are based on drop-cast Cu TCNQ crystals. © 2019 The Author(s)

Aluminum (Al) nanopowders have potential applications as hydrogen storage medium, energetic materials, pigments, and for production of metal matrix parts via powder metallurgy, to name a few. They are synthesized by methods which are either expensive or result in the product with impurities. A novel methodology based on ultrasonication of commercially available Al foil has been developed for synthesis of Al powders. Al foil was immersed in an organic medium and subjected to ultrasonication in a 160-watt bath ultrasonicator operated at 35 kHz frequency. Morphological, crystal structural, and dimensional characterization of ultrasonicated Al was carried out with the help of scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic forces microscopy (AFM) respectively. Characterization results revealed that Al foil was eroded laterally as well as axially, resulting in the formation of micro and nanosized flake-like pure Al powder.

Micropiles are suitable for underpinning and seismic retrofitting of structures. It is specially suitable for low head room area and can easily access congested areas where it is difficult to construct conventional piles. Its two basic functions are structural support and soil reinforcement. Literature review showed contradictory group effects on micropile behaviour subjected to vertical and lateral loading. This study is to investigate the response of micropile groups subjected to lateral load installed in loose sand (relative density 30%), in medium dense sand (relative density 50%) and in dense sand (relative density 80%). The group behaviour is found to be a function of the state of the sand, spacing of the micropile groups and length-to-diameter (L/D) ratio. Ultimate lateral resistances of micropile groups are maximum at 2D spacing in loose sand and in medium dense sand. In dense sand, maximum lateral resistance is observed in 6D spacing. Overall, it was observed that groups with higher L/D ratio had positive group effects. Modes of failure of the micropile groups are found to be a function of the length-to-diameter ratio and relative density of the sand.

An ordered semiconductor has a crystalline lattice in which charge carriers move around by the Gaussian process of normal diffusion. The mean square displacement (MSD) of these charge carriers is proportional to time. On the contrary, the movement of carriers in a material with a non-crystalline structure such as amorphous semiconductors is considered to be non-Gaussian in nature. In this case, MSD is proportional to some power of time. Diffusion in this type of transport mechanism is classified as anomalous diffusion. The usual drift-diffusion equation (DDE) cannot adequately describe this process because it has non-Gaussian and dispersive transport mechanisms. Fractional calculus has been used to generalize the standard DDE to a time fractional equation in order to include the hereditary effects of the carrier transport. For power devices, the distribution and conduction of heat is the primary criteria considered when making a device. Therefore, an equation for heat conduction is added to the model for inclusion of variable temperature. The coupled system is solved using a Numerical scheme wherein Finite Difference method has been employed to discretize the Riemann - Liouville time derivative of order α and the space variable. The effects of different physical factors such as light intensity, heat and applied electric field are discussed with the help of graphical illustrations.

Among a diverse set of properties, graphene is also noted for its electrochemical and catalytic capabilities. These can also be influenced by functionalization of graphene. This study reports the chemical functionalization of graphene oxide (GO) with an aromatic compound 4-hydroxy-4′-n-pentylbiphenyl, by an esterification reaction. Formation of new coupled product was investigated through scanning electron microscopy, X-rays diffractometer, Fourier-transform infrared, and UV–Vis spectrometry studies. UV–visible spectrometry also indicated an increase in band gap energy, likely due to the Burstein–Moss effect. Electrochemically, the esterified product was found to be better than GO in terms of triiodide reduction, which gives plausible worth to exploring this functionalization strategy further for the development of counter electrode materials for dye-sensitized solar cells.

Present analysis deals with the nanofluid flow due to a cylinder. Heat transfer mechanism is inspected under the physically acceptable convective type conditions. A simple isothermal model of homogeneous–heterogeneous reactions is used to regulate the solute concentration. Thermodynamics processes of homogeneous–heterogeneous reactions analyze the effect of temperature phase changes, such as convection or evaporation. It is assumed that the base fluid (water) is essentially composed of single and multi walled carbon nanotubes. Uniformly valid convergent series expressions are obtained with the help of optimal homotopic approach. Impacts of embedded flow parameters are visualized through graphical illustrations. Fluid velocity displays decreasing trend near the cylinder as the curvature parameter is incremented. Interestingly, such result is not preserved far from the cylinder. The simulations predict that wall heat flux is inversely proportional to both curvature parameter and the convecting heating strength. However, value of heat flux is predicted to be larger in case of larger volume fraction of carbon nanotubes. Moreover heat transfer coefficient is more in single wall carbon nanotubes (SWCNTs) when compared with multi wall carbon nanotubes (MWCNTs). Heterogeneous and homogeneous reactions have opposite behaviors on nanoparticle concentration distribution. Drag coefficient at the cylinder enhances when larger curvature parameter is accounted. Comparison of present study with previous published work is given. The results are found in good agreement.

Powder metallurgy processing is an adaptable method commonly used to fabricate Multi Walled Carbon Nanotubes Aluminum (MWCNTs/Al) nanocomposites because it is a simple method of composite preparation. In this research paper Functionalized Multiwalled Carbon Nanotubes (f-MWCNTs) with different weight percentage (0.1%, 0.5% and 1.0%), were reinforced into pure Aluminium (Al) matrix using powder metallurgy route in order to prepare f-MWCNTs/Al nanocomposite. Density analysis of the nanocomposite shows that mass density of the nanocomposites increases with increase in weight percentage of f-MWCNTs and also with increase in milling time. The hardness value depends highly on mass density, wt% of f-MWCNTs, milling time and also fine structure of the nanocomposite.

This article addresses a computational study for carbon nanotubes with diffusion species. Mathematical analysis and modeling are formulated in the presence of slip effect, Darcy porous medium and chemical species. Diffusion coefficients are accounted as equal amount. Optimal Homotopy Analysis Method (OHAM) is implemented in taking care for convergence control parameters. Residual errors and its graphs are plotted for CNTs nanofluids. The current data is compared with the previous published work. The results are found in favorable agreement. Physically interesting parameters are highlighted. The velocity is dominated for MWCNT than SWCNT. The velocity profile increases for power index when m>1 while opposite trend is observed for power index when m