A green approach for modification and functionalization of wool fabric using bio- and nano-technologies

In the present work, we propose a green and sustainable strategy for eco-friendly surface modification of wool structure using biosynthesized kerationlytic proteases, from C4-ITA-EGY, Streptomyces harbinensis S11-ITA-EGY and Streptomyces carpaticus S33-ITA-EGY, followed by subsequent environmentally sound functionalization of the bio-treated substrates using ZnONPs, ZrO₂NPs, ascorbic acid and vanillin, individually, to provide durable antibacterial as well as UV-protection properties. Both surface modification changes and the extent of functionalization of the final products were characterized by SEM, EDX, antibacterial efficacy, UV-blocking ability, loss in weight, nitrogen content and durability to washing analysis. The obtained data reveal that the developed green wool fabrics exhibit outstanding durable antibacterial activity and UV-blocking ability for fabricating multi-functional textile products that can be utilized in a wide range of sustainable protective textiles, irrespective of the used post-finishing formulation ingredients. The results also show that both modification and functionalization processes are governed by the type of enzyme and kind of active material respectively. Moreover, the biosynthesized kerationlytic proteases could be accessibly used to remove protein-based stains like blood and egg.

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Impacts of slip and mass transpiration on Newtonian liquid flow over a porous stretching sheet

This article focuses on analytic solutions for Newtonian fluid flow with slip and mass transpiration on a porous stretching sheet using the differential transform method and Pade approximants of an exceptionally nonlinear differential equation. The impacts of different parameters including mass transpiration (suction/injection), Navier's slip, and Darcy number parameters on the velocity of the liquid and tangential stress are discussed. A comprehensive comparison of our results with the previous one in the literature is made, and the results showed good agreement. An investigation is conducted of a combination of magnetic liquids that are conceivably pertinent for wound medicines, skin repair, and astute coatings for natural gadgets. It is found that there is a decrease in the velocity profiles and the boundary layer thickness for the case of suction.     

A new application of giant reed waste material for ammonium removal

Excess nitrogen is one of the main causes of eutrophication in water bodies. In this study, the undesirable agricultural lignocellulosic material giant reed was used to remove ammonium ions from aqueous solutions. Batch experiments were conducted to investigate the effect of various parameters such as contact time, initial ammonium concentration, adsorbent dosage, pH, particle size, agitation rate and phosphate coexisting during the ammonium adsorption process. The ammonium sorption capacity of fibrous giant reed (FGR) at equilibrium was 12.49?mg?N/g with a maximum removal efficiency of 76% observed within 30?min at pH range of 6.5–9.5. Results revealed that the Freundlich isotherm model fitted better with the sorption process than the Langmuir model, and the adsorption process was well described by pseudo-second-order kinetic model. FT-IR analyses indicated that complexation and ion exchange could be the main mechanisms for the ammonium removal by FGR. Results revealed that FGR has a sorption capacity comparable to that of other natural sorbents with the advantage of greater availability with no cost.     

Alternative Approaches to Modeling time Variation in the Case of the U.S. Real Interest Rate

This paper compares three approaches for modeling time variation in the U.S. real interest rate: a three-state Markov switching model as estimated by Garcia and Perron (1994), a random-walk model with two-state Markov switching variance, and a time-varying parameter model with two-state Markov switching variance. The findings are generally supportive of modeling continual change in the mean of the real rate process rather than employing a model that limits variation in the mean to a specified number of states.     

Thermal convection of MHD Blasius and Sakiadis flow with thermal convective conditions and variable properties

Microsystem Technologies - A theoretical study on the effect of magnetohydrodynamic field on the classical Blasius and Sakiadis flows of heat transfer characteristics with variable conditions and...     

Mass transfer of viscous gas flow over porous stretching/shrinking sheet in the presence of slip and mass transpiration

The effect of the mass transpiration parameter on the viscous gas flow past a porous stretching/shrinking sheet in the presence of Navier's slip is investigated, and also, the mass transfer characteristics are examined. The physical flow problem executes the Navier–Stokes and the mass equation, which forms the system of nonlinear partial differential equations. These are transformed via similarity variables into a system of ordinary differential equations. The slip flow model of the total mass transfer on the moving sheet is modeled by introducing gas slip velocity. The total mass transfer on the moving sheet is modeled by inducing slip models of first and second order. Further, the suction which induces the slip velocity as opposed to the surface movement is examined. The mass suction-induced slip forces the adjacent gases to flow in the reverse direction to sheet movement. Thus, the solution space expands with the slip-induced suction and sheet movement. In the mass injection case, the induced slip increases the effect of the fluid flow for sheet movement. Upon all previous flow models, the present investigation is significant due as it investigates the mass transfer of viscous gasses flow past a porous medium in the presence of slip and mass transpiration.     

Clouding Behavior of C13EOx (x = 10–19) Micelles in a Wide Range of Salinity and Hardness: Concomitant Effects of Salinity and Degree of Ethoxylation

The effect of salinity and degree of ethoxylation on the cloud point, T_cp, in C₁₃EO_x (x = 10–19) micelles was investigated in distilled water and in the salinity range S = 1.96–196 g L⁻¹. At a fixed x value, the rate dT_cp/dS was given by dT_cp/dS = α _b + β _bS with α _b < 0 and β _b > 0. This trend suggests that dT_cp/dS is the result of two opposing effects, an entirely (negative) surfactant-dependent effect (α _b) and a combined (positive) surfactant-solvent (β _bS)-dependent effect. In addition, the rate dT_cp/dS was found to become increasingly less negative with increasing salinity (dT_cp/dS) < 0), suggesting an overwhelming contribution of the α _b effect as compared to the β _bS effect. On the other hand, at fixed S, the rate was given by dT_cp/dx = α _x + β _xx with α _x > 0 and β _x < 0. This trend also suggests the existence of two opposing effects, a strictly (positive) solvent-dependent effect (α _x) and a concomitant solvent (β _x)-surfactant (x)-dependent effect. Contrary to dT_cp/dS, the rate dT_cp/dx was found to become increasingly less positive with increasing x values (dT_cp/dx > 0), suggesting that α _x is the dominant factor in the surfactants’ susceptibility to be salted in. Both constants α_b and α _x were attributed to a dual temperature-salinity effect on the structure of water molecules not involved in surfactant's hydration. On the other hand, β _b and β _x were associated with the change in the structure of water due to the dehydration of surfactants’ oxyethylene moieties with increasing temperature.     

Synthesis of PVA/PVP based hydrogel for biomedical applications: a review

The composition and synthesis of hydrogel were developed by using Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP). Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP) based hydrogels are the most popular water-soluble, biodegradable, biocompatible, non-carcinogenic, and extremely low cytotoxicity synthetic polymers due to their good biocompatibility have been used in numerous biomedical applications, such as implants, artificial organs, drug delivery devices, and wound dressings. In this review paper, details of synthetic of hydrogel formulations with PVA and PVP for biomedical applications.