Light Fastness and Shade Variability of Tannin Colorant Dyed Wool with the Effect of Mordanting Methods

Mordanting methods effect on color characteristics and fastness properties, particularly light fastness were evaluated in this study. Effect of metal mordants and their combinations on wool dyeing with Terminalia chebula natural dye were investigated and correlation between dye structures, effect of metal mordant and mordanting methods were established. Results reveal that T. chebula can be used as yellow dye with or without metal mordants to get a variable range of shades on wool with good color strength and fastness properties, and appreciable shade variations with mordanting methods observed. Color performances of dyed substrate indicated substantial improvement in depth of shades and color fastness in case of mordanted samples. Pre-mordanting with tin and post-mordanting with alum proved to be most effective for increasing K/S values of the dyed substrate under the optimum dyeing conditions.     

Sonosynthesis of Microcellulose from Kenaf Fiber: Optimization of Process Parameters

Green composites using cellulose fibers as a reinforcement material provide a sustainable and renewable alternative to petroleum-based polymers. However, controlling the usage of chemicals and processing parameters to extract the cellulose could be sometimes difficult. Therefore, this study aims to optimize the conditions for extracting the microcellulose from kenaf fibers using central composite design (CCD), a statistical tool in design of experiments. Three factors and three levels were chosen for carrying out the analysis. The design was based on sodium hydroxide (NaOH) dosage, Sodium Chlorite (NaClO₂) dosage and sonication time as independent variables, while dependent variables were the fiber size and degradation point. Later, size responses were fitted using quadratic polynomial model and degradation responses using 2-factor interaction model (2FI). The R² values of 0.89 and 0.83 were obtained for the quadratic and the 2FI model, respectively. Further, surface morphology, thermal analysis, Fourier transform infrared (FTIR) spectroscopy and X-Ray diffraction (XRD) were also used for design validation. Optimal parameters for microcellulose extraction were found to be 0.15 g of NaOH at first stage, 4.6 mL of NaClO₂ at second stage, and 10 min of sonication during third stage.     

Effect of Binary and Ternary Combination of Metal Salt Mordants on Dyeing and Fastness Properties of Natural Protein Fibre with Juglans regia L. Dye

The present article focuses on the effect of different combinations of metal mordants on color characteristics and fastness properties of natural dye extracted from Juglan regia L bark powder. The influence of different types of mordant combinations such as alum + ferrous sulphate, alum + stannous chloride, ferrous sulphate + stannous chloride, and alum + ferrous sulphate + stannous chloride on color parameters has been investigated in terms of CIELab (L*, a*, b*, c*, and h°) and K/S values. The fastness properties with respect to light, washing, and crocking of developed shades were determined according to ISO and AATCC test methods. Based on the experimental results, it has been found that 96 shades with novel and fashionable hues were produced by the use of these metal salt combinations. It was also found that all mordanted samples had satisfactory light and wash fastness ratings. Dry rub fastness was found relatively better than wet rub fastness.     

Drying Models and Quality Analysis of Sun-Dried Ciku

Sun drying of ciku (Manilkara zapota) was carried out on different sample sizes to investigate the effects on drying kinetics. It was found that the maximum drying rates of sun-dried ciku decreased with larger product size. Three sunny days are needed to dry the ciku slabs to an average final moisture content of 0.2 g H₂O/g dry mass. The results showed that hardness and chewiness of the dried samples were significantly different (p < 0.05) compared to fresh ciku slabs and commercial dried fruit. The color measurement of dried product showed that L? and b? values significantly decreased (p < 0.05), whereas the a? value increase was not significantly different (p > 0.05) compared to fresh ciku slabs. In addition, sun-dried ciku retained a total polyphenol content (TPC) that was relatively low (p < 0.05) compared to fresh ciku.     

Artificial Neural Network Modeling of the Deposition Rate of Lactose Powder in Spray Dryers

A spray dryer is the ideal equipment for the production of food powders because it can easily impart well-defined end product characteristics such as moisture content, particle size, porosity, and bulk density. Wall deposition of particles in spray dryers is a key processing problem and an understanding of wall deposition can guide the selection of operating conditions to minimize this problem. The stickiness of powders causes the deposition of particles on the wall. Operating parameters such as inlet air temperature and feed flow rate affect the air temperature and humidity inside the dryer, which together with the addition of drying aids can affect the stickiness and moisture content of the product and hence its deposition on the wall. In this article, an artificial neural network (ANN) method was used to model the effects of inlet air temperature, feed flow rate, and maltodextrin ratio on wall deposition flux and moisture content of lactose-rich products. An ANN trained by back-propagation algorithms was developed to predict two performance indices based on the three input variables. The results showed good agreement between predicted results using the ANN and the measured data taken under the same conditions. The optimum condition found by the ANN for minimum moisture content and minimum wall deposition rate for lactose-rich feed was inlet air temperature of 140°C, feed rate of 23 mL/min, and maltodextrin ratio of 45%. The ANN technology has been shown to be an excellent investigative and predictive tool for spray drying of lactose-rich products.     

Tailoring structural,morphological and mechanical characteristics of mono-crystalline diamond-reinforced polyacrylonitrile based electrospun fibers

Composites of diamond-reinforced particles offer extraordinary thermal- and mechanical characteristics attributable to their manageable outer surface and huge available uppermost layer. Uniform distribution of diamond powder in polymeric matrix, and enhanced interactions between them are the two significant problems to attain robust polymer composites. In this work, the crystalline diamond particles as received and chemically modified ones were integrated in polyacrylonitrile (PAN) matrix uniformly by electrospinning method. This procedure avoided agglomeration of the reinforced diamonds through uniform distribution in the polymer matrix. The shapes of diamond-integrated PAN fibers were attuned by adapting diamond loading, polymer concentration, flow rate, and applied voltage to achieve beads free fibrous structures. PAN was chosen as a carrier polymeric-matrix to enhance the electrostatic forces between functionalized diamond-particles and PAN molecular chains. Tensile tests showed that the loading of 2 wt% modified diamond-particles improved Young’s modulus of fibers by 74.94% and tensile strength by 125%. Therefore, modification of the outer surface of the diamond particles improved the chemical interactions between the diamond surface and matrix, and stress was transferred to the diamond particles in composite fibers. Additionally, thermal stabilities of the diamond-based polymer composites were enhanced by the integration of diamond powder in composite fibers.

     

Intraspecific variation in spermoderm pattern of tribe Acacieae (Mimosoideae) using scanning electron microscopy techniques

Current research carried out in Pakistan is the first report on spermoderm ornamentation of eight species of tribe Acacieae (Mimosoidae) by using scanning electron microscopic techniques representing two genera, Fedherbia and Acacia were examined. Different spermoderm ornamentation were observed, described and discussed for their taxonomic importance. Seeds surfaces of the studied tribe possess novel variations in macro and micro morphology. Great variations were observed in both qualitative and quantitative characters of seeds. Seeds shape was oblong, ovate to elliptical and spermoderm ornamentation was levigate, rugose, polygonal and discoid, colliculate, and papillose type. These variations in the spermoderm ornamentation can be used as an aid in identification and classification of the members of tribe Acacieae.     

Recent trends in biodiesel production from commonly used animal fats

Changes in climate due to the enormous amount of carbon dioxide emissions have really encouraged the development of energy sources that are renewable, sustainable, and eco‐friendly. The development of alternative energy sources can also be attributed to the rapid decrease in resources of fossil energy. Biodiesel has gained significant interest in recent years due to its fossil fuel–like properties and sustainable and eco‐friendly characteristics. However, most biodiesels are expensive because of the high cost of feedstock largely based on edible vegetable oil sources. The use of animal fats waste as cost effective feedstock in biodiesel production has gained considerable attention in recent years. Although, most studies regarding the use of animal wastes as feedstock in biodiesel production are still in the early stages, the advantages of this type of feedstock have been highlighted in the literature. However, most studies have not focus on the recent advances in the use of animal fats waste. The studies on the use of novel approach have been reported in isolation. Therefore, this current study attempts to highlight recent developments of the most commonly used animal fats waste in the production of biodiesel. In addition, emphasis was given to the most appropriate production technique, catalyst, energy requirement, and optimum reaction conditions.