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The purpose of this paper is to analyze the stress‐relaxation behavior of different woven fabrics under constant torsional strain in a wrinkled state. For this purpose, a new method for determination of stress‐relaxation behavior of the fabric was used while keeping the torsional strain constant.

In this study, the behavior of stress relaxation of fabric is examined with modification of wrinkle force tester sophisticated electro‐mechanical method and fabricating a device which uses a computer and micro controller, with constant torsional strain by a rotational level of 9.1 turn/m in 280°, and in 300 s.

The results depict that stress‐relaxation percentage in fabric in weft alignment is more than warp alignment and the fabrics which tolerate more torsional force, possess less stress‐relaxation percentages. In this way, with increasing polyester percentage in fabric the scale of stress‐relaxation percentage decreases. Also, adoption of data derived from experiments with Maxwell model shows that the interlaced model is a suitable model for explaining the stress relaxation decline in fabric. Correlation coefficient of fabrics in weft alignment with Maxwell model is more than warp alignment.

This study has practical implications in the clothing as well as in technical textiles areas.

Knowing visco‐elastic properties is very important. However, there is no information available to study the stress relaxation of woven fabrics under the combined influences of compression and constant torsional strains.

The purpose of this paper was to identify Serratia marcescens to extract and purify prodigiosin pigment to evaluate the antibacterial potential of the pigment.

Samples were collected from shrimp aquaculture ponds. Species identification was conducted using morphological, biochemical and molecular tests. Pigment extraction and purification were carried out using column chromatography. The antibacterial effect of crude and purified prodigiosin pigment was evaluated on Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus as biofouling bacteria. In addition, the interaction between prodigiosin and proteins involved in biofilm formation was evaluated using molecular docking.

The results of prodigiosin extraction with solvents showed the highest percentage of pigment presence with methanol solvent in the second day of culture. The chemical structure of pure prodigiosin obtained from the column chromatography was confirmed by Fourier-transform infrared spectroscopy. Both crude and purified pigments exhibited antibacterial effects against selected bacterial strains. The antibacterial effect of the purified pigment was higher, and the highest antibacterial effect was observed on B. subtilis. Prodigiosin docking was carried out with all target proteins, and the docked energy in all of them was at an acceptable level.

Prodigiosin extracted from S. marcescens can be used as a bioactive compound to design and manufacture of anti-biofouling and anti-biofilm formation products to use extensively for industrial applications as a natural color in marine industries, food industry, cosmetics and textile productions.

This paper aims to investigate the effect of titanium dioxide (TiO₂) nanoparticle coating on the visible reflectance and color appearance of dyed cotton fabrics.

A Taguchi experimental design model was used to minimize the number of samples and for accurate prediction of possible responses. The governing parameters affecting the color change of dyed fabrics through the coating process were selected as shade of cotton fabrics, depth of shade, concentration and size of TiO₂ nanoparticles and concentration of citric acid. The Taguchi model suggests the L18 orthogonal array. In the meantime, the lower response category was selected to determine the optimum conditions. According to obtained results, coating with TiO₂ nanoparticles results in color change (ΔEab*) of all dyed cotton fabrics.

The obtained results indicate that the TiO₂-coated fabrics had higher reflectance compared to raw fabrics. Furthermore, it was found that the TiO₂ pigmented coating increases the brightness of samples and simultaneously decreases their chroma. On the other hand, analysis of variance reveals that the concentration of TiO₂ nanoparticles together with shade of fabrics has the most significant impact on the color change of dyed fabrics through coating process. Dye concentration and size of TiO₂ particles also, to the same extent, had influence over the color change. However, the effect of the concentration of citric acid on the color change was insignificant.

This research investigates the effect of TiO₂ nanoparticles on the optical property of colored fabric by using a Taguchi experimental design model to minimize the number of samples.