Using sound pressure level and vibration velocity method to determine sound reduction index of lightweight partitions

Nowadays, lightweight building structures are widely used by the construction industry as a more natural and cost-effective method. The purpose of this study is to compare between sound pressure level and vibration velocity method for sound reduction index determination for single- and double-leaf gypsum board partitions. The sound pressure level method was carried out according to the requirements of ISO 140-3:1997, and the vibration velocity method (V) was carried out according to some criteria of ISO 10848-1:2006. Regarding double-leaf partitions, measurements were carried out with the leaves separated by 5- and 10-cm air gaps. The effect of cavity filling with absorbing materials was studied experimentally. The space between the leaves was filled with Rockwool and polyurethane to illustrate the effect of cavity absorption on the sound reduction index behavior. It was found that there is good agreement between the two methods. Also, cavity filling with a 10-cm absorbing material such as Rockwool increases the sound reduction index at the critical frequency by 7 dB using sound pressure method and 4 dB using vibration velocity method. </jats:p

Investigating the performance of drug delivery system of fluconazole made of nano–micro fibers coated on cotton/polyester fabric

Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs and to render them safer, more effective and reliable. Long-term or repeated use of oral administration of fluconazole for treating chronic candidiasis in the patient and partially abandoned treatment lead to the resistant strains of the fungus Candida albicans and severity of the disease. In this study, the use of nanofibers and microfibers containing fluconazole for local drug delivery to increase the efficiencies and reduce the side effects caused by taking the drug was studied. Morphology, microstructure and chemical composition of PVA nanofibers containing fluconazole were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). As well as, the DSC test was indicated presence of fluconazole in PVA fibrous mats. The rate of drug release was investigated by UV-Vis spectrophotometery and swelling technique. SEM images showed that the nanofibers with uniform structure without beads were produced. The mechanical properties of the pristine PVA nanofiber and fibrous mat containing drug were evaluated. The release of fluconazole from PVA nanofibers in pH of 7.4 and at 37 degrees C was investigated. The results presented that the drug release rate is dependent on the morphology and structure of PVA nanofibers and could be adjusted in desired dosage. The presented products are applicable in the high production form for medical textile industry