the effects of operating parameters such as feed temperature and permeate-side pressure on the performance of a commercial pva membrane in the dehydration of toluene by a pervaporation (pv) membrane system is studied in the present work. the results obtained indicate that increasing temperature in the range of 40 to 70 °c and reducing permeate pressure in the range of 1 to 10 mmhg increase memb...

In this paper, we studied a new preparation method of microcapsules for entrapment of genetically engineered cells. Polyvinyl alcohol microcapsules having well defined shape, high mechanical strength, good biochemical and permeability properties were prepared by using low temperature physical cross-linking method. Comparing with currently used alginate-polylysine-alginate microcapsules, polyvin...

Alpha-amylase was immobilized onto polyaniline-polyvinyl alcohol (PAni-PVA) film by cross linking with glutaraldehyde. The activity yield and immobilization efficiency was calculated as 13.58% and 30.60% respectively. The PAni-PVA-Amylase films were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and amylase activity assay. The immobilized α-amylase had its optimum activity at p...

the starch based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. in the present research, the polyvinyl alcohol (povh), as a compatible polymer, and montmorillonite (mmt) nanoclay, as a nanofiller, were added to plasticized starch film (ps) to improve its properties and also to produce ps-mmt-pvoh nanoco...

A solid-state laser based on a dye-doped deoxyribonucleic acid (DNA) matrix is described. A thin solid film of DNA has been fabricated by treating with polyvinyl alcohol (PVA) and used as a host for the laser dye Rhodamine 6G. The edge emitted spectrum clearly indicated the existence of laser modes and amplified spontaneous emission. Lasing was obtained by pumping with a frequency-doubled Nd:YA...

Photoisomerization of l,4-diphenyl-l,3-butadiene (DPB), l,6-diphenyl-l,3,5-hexatriene (DPH) and l,8-diphenyl-l,3,5,7-octatetraene (DPO) in polyvinyl alcohol) (PVA) films was studied unter daylight and direct irradiation. The most efficient photoisomerization occurs in the DPB molecule, the smallest among the compounds investigated. For the greatest, DPO, molecule no distinct isomerization was o...