Fractal Approach to Hierarchically Evolved Laser Processed CaP Coatings

This paper discusses a fractal approach to understand nature inspired laser surface engineered coatings. Via a laser surface engineering process a multi‐scale CaTiO₃ coating was synthesized on Ti alloy surface. At faster laser processing speeds star like CaTiO₃ features evolved inside rings rich in calcium phosphate and TiO₂. The porosity developed through the distribution of these particles results in a multi‐scale distribution. Fractal analysis revealed that such laser processed surfaces had consistent fractal dimension over multiple length scales. This multi‐scale and multi‐phase surface microstructure contributed to enhanced biomimetic precipitation.     

Effect of microwave pretreatment on the dyeing behaviour of polyester fabric

Polyester fabric (filament by filament) was pretreated in a microwave oven in the presence of solvents and subsequently dyed with commercial disperse dyes [Dispersol Red C‐B (CI Disperse Red 91) and Dispersol Blue B‐G (CI Disperse Blue 26)] at different temperatures and for different durations of time. It was observed that the solvent interaction with the polyester could be enhanced by using microwave heating. Solvent molecules interact rapidly, not only with the surface of the fibre but also with the interior parts. Scanning electron microscope results showed that structural modifications take place, which produce surface roughness and voids. This enhances the dye uptake by threefold in comparison to conventional methods.     

Effect of pH on the physicochemical properties of starch films

We demonstrate a simple approach of using highly alkaline starch solutions to obtain films with high flexibility and improved water resistance. Extensive studies have been done to develop films from starch, primarily for food applications. However, films developed from starch are brittle and generally chemical modifications or plasticizers are used to improve the flexibility and other properties of starch films. Such modifications make starch expensive, decrease biodegradability, and affect the morphology and subsequent processing of starch. In this research, we have prepared films using starch solutions at pH between 3 and 11. Starch solutions having different pHs were made into films and the tensile, thermal properties, and resistance to water were studied. It was found that preparing starch with pH 11 solution imparts high flexibility without any apparent physical damage. Films prepared under strong acidic and alkaline conditions also had considerably reduced hydrophilicity, which is required for food packaging and other applications. The films prepared at alkaline pH show nearly 50% reduction in water sorption and an increase in elongation. The films obtained from alkaline pH are flexible and water resistant and can potentially be used to develop various bioproducts. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48563.     

Detergent‐Compatible Robust Alkaline Protease from Newly Isolated Halotolerant Salinicoccus sp. UN‐12

Currently, enzyme‐containing blended detergent preparations are favored in the detergent industry. The detergent compatibility of an enzyme depends on its robustness to withstand harsh operating conditions and maintain efficient functioning in the presence of various surfactants and detergents. Alkaline proteases from halotolerant microbes having the capability to work in demanding environments are desirable for their application in the detergent industry. The protease secreted by a halotolerant soil isolate Salinicoccus sp. UN‐12 was evaluated for its suitability in detergent formulations. The studied enzyme is an alkaline serine protease (63 kDa) with an optimum temperature of 55 °C and optimum pH of 8.5. The protease was purified 17‐fold with a 4% yield. The protease was active in NaCl (up to 4 mol) and showed enhanced activity in the presence of CaCl₂, KCl, and MnCl₂. In addition, the proteolytic activity was sustained in the presence of various organic solvents, cyclodextrin, disodium cocoamphodiacetate, ionic liquids, hydrotropes, and ultrasound. This report is the first to document the multifarious robustness and novel attributes of a protease secreted by the newly isolated Salinicoccus sp. UN‐12. The protease‐detergent formulation efficiently removes blood, egg, grass, and tomato sauce stains. This protease is now available for efficient and eco‐friendly applications in the detergent industry.     

Isolation of a Δ5 Desaturase Gene from <Emphasis Type="Italic">Euglena gracilis</Emphasis> and Functional Dissection of Its HPGG and HDASH Motifs

Delta (Δ) 5 desaturase is a key enzyme for the biosynthesis of health-beneficial long chain polyunsaturated fatty acids such as arachidonic acid (ARA, C20:4n-6), eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) via the “desaturation and elongation” pathways. A full length Δ5 desaturase gene from Euglena gracilis (EgΔ5D) was isolated by cloning the products of polymerase chain reaction with degenerate oligonucleotides as primers, followed by 5′ and 3′ rapid amplification of cDNA ends. The whole coding region of EgΔ5D was 1,350 nucleotides in length and encoded a polypeptide of 449 amino acids. BlastP search showed that EgΔ5D has about 39 % identity with a Δ5 desaturase of Phaeodactylum tricornutum. In a genetically modified dihomo-gamma-linoleic acid (DGLA, C20:3n-6) producing Yarrowia lipolytica strain, EgΔ5D had strong Δ5 desaturase activity with DGLA to ARA conversion of more than 24 %. Functional dissection of its HPGG and HDASH motifs demonstrated that both motifs were important, but not necessary in the exact form as encoded for the enzyme activity of EgΔ5D. A double mutant EgΔ5D-34G158G with altered sequences within both HPGG and HDASH motifs was generated and exhibited Δ5 desaturase activity similar to the wild type EgΔ5D. Codon optimization of the N-terminal region of EgΔ5D-34G158G and substitution of the arginine with serine at residue 347 improved substrate conversion to 27.6 %.     

Preparation and characterization of polysulfone–cyclodextrin composite nanofiltration membrane: Solvent effect

α-Cyclodextrin membranes were prepared by the phase inversion method using four types of casting solvents such as N-methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethyl acetamide (DMAc), and dimethyl formamide (DMF) herein-after termed as α-CD-NMP, α-CD-DMSO, α-CD-DMAc, and α-CD-DMF, respectively. The membranes were characterized by IR, XRD, TGA-DTA, DSC, and SEM analysis and show that solvents like NMP, DMA, DMF give good uniform morphological membranes and are better than that of DMSO. Thermal decompositions of the pure polymer and composite membranes indicate different range of thermal degradation of the membrane. This study reveals that the casting solvents NMP, DMF, DMAC have nearly same significant effect on morphology and other properties of the membranes. This is explained in terms of demixing behavior of the polymer and the combined effect of solvent volatility and polymer–solvent interactions as estimated from Hansen solubility parameter. Solvent hydrophobicity also affects the performance of the membrane and can be determined in terms of water permeability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Utilizing discarded plastic bags as matrix material for composites reinforced with chicken feathers

High‐ density polyethylene (HDPE) in used plastic bags was reinforced with chicken feathers to develop composites in an effort to add value and reduce the amount of the plastics and feathers disposed in landfills. Feathers are biodegradable, derived from renewable resource, and are inexpensive and HDPE in plastic bags is mostly discarded in landfills. Utilizing feathers as reinforcement for HDPE composites will provide an opportunity to develop environmentally friendly composites. In this research, HDPE plastic bags were reinforced with chicken feathers and the flexural, tensile and acoustic properties were studied. It was found that incorporating feathers substantially improved the flexural properties and tensile modulus. At the optimum condition, the HDPE‐feather (50/50) composites had flexural strength of 13.9 MPa and stiffness of 0.45 N/mm compared to 9.8 MPa and 0.29 N/mm for 100% HDPE. The 50/50 HDPE‐feather composite had similar tensile strength but more than twice the tensile modulus of neat HDPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Pyrolysis of grain screenings in a batch reactor

A preliminary study of the pyrolysis of grain screenings (wheat) has been carried out using a batch pyrolysis unit operating at atmospheric pressure. Grain screenings are the materials removed mechanically from grains (wheat, rapeseed, barley, etc.) by cleaning or separating equipment in grain elevators. Reaction conditions were varied to determine the effect of these changes on the final product (tar, gas, and char). The reaction variables manipulated included temperature (600–800°C), nitrogen carrier gas velocity, and potassium carbonate catalyst. It was found that the yields of ethylene were higher than those of ethane. These hydrocarbons were accompanied by smaller but significant yields of hydrogen and C₄ to C₆ hydrocarbons. The grain screenings impregnated with 15 wt% potassium carbonate catalyst gave higher synthesis gas yields with a H₂/CO mole ratio up to 4.1. With the experimental set up used in the present study, the mass balances achieved were low and ranged between 65 and 77% of the weight of the grain screenings used.