probable use of chemical and biochemical detergents to wash polysulphone membranes using in milk ultrafiltration needs a multidisciplinary investigation. by increasing use of these membranes in food processing, washing and recovery of initial permeate flux, in order to use for a longer time from this technology, has much importance. in this research, influence of chemical detergents including e...

the role of polymeric additives such as pvp and peg is studied with respect to the morphology of pes porous layer as a sublayer of nanofiltration composite membranes based on pes/pa. results show that by phase inversionprocess of quaternary systems comprised of four components of polymer/solvent/non-solvent/additive and the diffusion of intertwined polymers some changes occur in membrane morpho...

objective: the aim of this study was to estimate the frequency of preterm birth (ptb) and premature rapture of membranes (prom) and their associations with maternal factors. material and methods: this cross sectional study was carried out at akbar-abadi hospital in tehran during january 2009-aprile 2010. four hundred sixty six primiparous women with gestational age more than 20 weeks and single...

background: there is evidence of antibacterial properties of human chorioamniotic layer. however, the distinctive contribution of its individual parts, amniotic and chorionic membranes, to these effects is still unknown. the aim of present study was comparison of the antibacterial effects between amniotic and chorionic membranes. methods: chorioamniotic layer was removed from placenta belonging...

In this work, we prepared the nafion/montmorillonite/heteropolyacid nanocomposite membranes for direct methanol fuel cells (DMFCs). The analyses such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) were conducted to characterize the filler dispersion and membrane structure in prepared nanocomposite membranes. XRD patterns of nafion-CsPW-MMT ...

We consider DNA-cationic lipid complexes that form lamellar stacks of lipid bilayers with parallel DNA strands intercalated in between. We calculate the electrostatically induced elastic deformations of the lipid bilayers. It is found that the membranes undulate with a periodicity that is set by the DNA interaxial distance. As a consequence the lamellar repeat distance changes resulting in a sw...

One of the limiting factors in good performance of forward osmosis (FO) membranes is the internal concentration polarization (ICP). To reduce ICP, thin film nanocomposite forward osmosis (TFN-FO) membranes were fabricated by adding different amounts of graphene oxide (GO) nanoplates (0-1 wt. %) to polymer matrix of polysulfone (PSf) substrate. The prepared nanocomposite membranes exhibited both...

Reverse osmosis (RO) is a water purifcation technology that uses a semipermeable membrane to remove ions, molecules, and larger particles for the production of drinking water. The frst RO membrane for seawater desalination, wastewater treatment and other applications were made of cellulose acetate. But, the polyamide thin-flm composite membrane that can tolerate wide pH...

New bionanocomposite proton exchange membranes were prepared from sulfonated polybenzimidazole (s-PBI) and various amounts of sulfonated ZnO/cellulose nanohybrids (ZnO/cellulose-SO3H). The use of ZnO/cellulose-SO3H compensates for the decrease in ion exchange capacity of membranes observed when non-sulfonated nano-fillers are utilized. The strong –SO3H/–SO<su...

background: rupture of fetal membranes can occur at any gestational age. premature rupture of membranes (prom) means rupture of fetal membranes before the onset of labor. objective: the purpose of this study was to evaluate and compare the reliability of the vaginal washing fluid urea and creatinine for the diagnosis of prom and to determine cut-off values. materials and methods: a total of 179...