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 ...

the aim of this investigation was to assess the effect of different antioxidants on the motility andmembrane integrity of the ram semen during storage at 5ºc for 0, 12, 24, 48 and 72 hrs after collection anddilution. a total of 57 ejaculates from 12 bakhtiary rams was collected by artificial vagina and were extended1 : 3 with egg yolk-citrate buffer, which was containing one of the following an...

background: understanding some part of the human body such as serous membrane, peritoneal cavity, lesser sac and proper mesentery is difficult for medical students. the objective of this study was to determine the effect of animal dissection on improving medical student knowledge and view related viscera and serous membrane anatomy. methods: in yums in 2011, sixty eight medical students were ra...

this paper deals with the extraction of l-theanine containing aliquat 336 as a carrier and cyclohexane as solvent across bulk liquid membrane. the optimum operation condition are as follows: extraction time of 150 min, initial concentration of theanine in the feed phase is 1.8 g/l, the carrier concentration is 0.5 m, the ion of the receiving phase is 0.2 m nacl of na2hpo4-nah2po4 buffer solutio...

akin type (asymmetric) reverse osmosis membranes undergo an irreversible osmotic dehydration upon coming into contact (skin side) with salt solutions. the extent of consequent changes (in appearance; decrease in linear dimension, water flux and salt rejection) are dependent on the salt concentration. these observations are correlated with the expected morphological changes taking place during d...

background and aim: the aim of the present study was to compare coronally advanced flap (caf) with amniotic membrane to caf with connective tissue graft (ctg) in the treatment of miller’s class iⅈ gingival recessions. materials and methods: 11 systemically healthy patients, with 30 miller’s class і and іі gingival recessions ≥3 mm, were selected and randomly divided into two equal groups. gi...

â a model is developed for separation of multicomponent gas mixtures in a countercurrent hollow fiber membrane module. while the model’s solution in countercurrent module usually involves in a time consuming iterative procedure, a proper initial guess is proposed for beginning the calculation and a simple procedure is introduced for correcting the guesses, hereby the cpu time is decreased ess...

bacteriorhodopsin operates as a light/proton transfer pump which converts the light energy into a proton gradient. energy stored in the proton gradient can be used in a variety of ways. bacteriorhodopsin producing sources are some halobacterium species such as halobacterium sodomense and halobacterium salinarum which continue to grow in harsh and salt-saturated conditions. two types of red pigm...

purpose: to evaluate the properties of cultured limbal stem cells for corneal surface reconstruction. methods: specimens of limbal explants were prepared from the eye bank of i.r. iran. the explants were cultured and expanded on acellular amniotic membrane for 21 days. the cultured cells were evaluated for expression of connexin 43 and keratinine k3 by immunocytochemistry and expression of k12 ...