An investigation in the use of ozone gas in the bleaching of cotton fabrics

WOS: 000250445700003Ozone, composed of three atoms of oxygen, can be used to oxidize many inorganic and organic impurities. Because of its high oxidizing capacity, the opportunities and parameters of ozone gas use in bleaching of cotton fabrics were researched in this study. It was found that in a very short time cotton fabrics can be bleached if the water content of cotton-woven fabric was 60% and the pH of the water impregnated was 7. Moreover, ozonation at room temperature was shown to be more efficient than ozonation at high to medium temperatures

Ozone bleaching of denim fabrics

Classic denim jeans are generally fabrics having indigo-dyed warp threads. Depending on the desired effect, a bleaching process can be carried out for denim fabrics. Suitable alternatives for oxidative bleaching with sodium hypochlorite and potassium permanganate are not currently available. Some potential alternatives (e.g., peroxide, glucose, and enzymatic bleaching with laccase) are relatively expensive. In this paper, ozonation of denim fabric was investigated as an ecological and practical bleaching alternative. Due to its effective oxidizing potential, denim fabric was treated with ozone; sufficient bleaching results were obtained in a very short time

Evidence for ∼80-75 Ma subduction jump during Anatolide-Tauride-Armenian block accretion and ∼48 Ma Arabia-Eurasia collision in Lesser Caucasus-East Anatolia

International audienceOrogens formed by a combination of subduction and accretion are featured by a short-lived collisional history. They preserve crustal geometries acquired prior to the collisional event. These geometries comprise obducted oceanic crust sequences that may propagate somewhat far away from the suture zone, preserved accretionary prism and subduction channel at the interplate boundary. The cessation of deformation is ascribed to rapid jump of the subduction zone at the passive margin rim of the opposite side of the accreted block. Geological investigation and 40Ar/39Ar dating on the main tectonic boundaries of the Anatolide-Tauride-Armenian (ATA) block in Eastern Turkey, Armenia and Georgia provide temporal constraints of subduction and accretion on both sides of this small continental block, and final collisional history of Eurasian and Arabian plates. On the northern side, 40Ar/39Ar ages give insights for the subduction and collage from the Middle to Upper Cretaceous (95-80 Ma). To the south, younger magmatic and metamorphic ages exhibit subduction of Neotethys and accretion of the Bitlis-Pütürge block during the Upper Cretaceous (74-71 Ma). These data are interpreted as a subduction jump from the northern to the southern boundary of the ATA continental block at 80-75 Ma. Similar back-arc type geochemistry of obducted ophiolites in the two subduction-accretion domains point to a similar intra-oceanic evolution prior to accretion, featured by slab steepening and roll-back as for the current Mediterranean domain. Final closure of Neotethys and initiation of collision with Arabian Plate occurred in the Middle-Upper Eocene as featured by the development of a Himalayan-type thrust sheet exhuming amphibolite facies rocks in its hanging-wall at c. 48 Ma