Green process for indigo dyeing: effect and modeling of physico-chemical parameters using statistical analysis

Textile Industries use different chemicals in indigo dyeing processes. Interest in eco-friendly processing in the textile industry has recently increased because of a larger awareness of environmental issues. For the case of indigo dyeing process, the reducing agent conventionally used is the - environmentally unfavourable - sodium dithionite, which will be replaced in this study with an ecological reducing agent called acetol that is also known as hydroxyacetone. In this paper, measurements of the redox potential at various experimental conditions were carried out in a dyeing bath, where acetol is the reducing agent of indigo. Moreover, an unconventional but eco-friendly indigo dyeing process of cotton was investigated. The effects of: reduction duration, dyeing duration, reduction temperature, alkalinity and the amount of indigo on the performances of this dyeing process were studied, and the dyeing results were evaluated by measuring the colour yield parameter [K/S] of the dyed samples at 660 nm. Finally, a factorial design was employed for the experimental plan; mathematical model equation and statistical analysis were derived by computer simulation applying the least squares method using Minitab 15

[First four cases of acute meningitis due to Toscana virus on monastir region]

Toscana virus [TOSV] has been identified as an important cause of acute meningitis in Italy where it was isolated for the first time. Currently, it is one of the major viral pathgens involved in acute meningitis in Mediterranean countries. We describe four cases of acute meningitis caused by TOSV concerning patients hospitalized in the department of infectious diseases, Fattouma Bourguiba university hospital, Monastir [Tunisia]. The demographic data, the clinical and laboratory features and the evolution were reviewed. All patients were male, living in coastal region. They were hospitalized in summer period. The mean age was 26 years. The diagnosis was suspected in the presence of fever and acute meningitis syndrome. Lumbar puncture showed clear cerebrospinal fluid [CSF] containing normal glucose and predominant lymphocyte. This diagnosis was confirmed by detection of anti-TOSV IgM in blood and CSF. The outcome was favorable in all cases. No specific treatment was administered. The mean follow-up was nine months