introduction: tympanoplasty is a standard procedure to repair tympanic membrane perforation. the aim of this study is to evaluate the results of tympanoplasty (hearing improvement and tympanic membrane closure rate) in patients suffering from chronic perforation of the tympanic membrane by considering the prognostic factors.  materials and methods: in a prospective study, based on the results o...

Exhibiting a very high surface area, good electrical conductivity and density of active sites, nitrogen-doped graphenic materials are considered as promising catalysts for the oxygen reduction reaction (ORR). Seldom studied in acidic media, N-doped foams were tested here cathode polymer electrolyte membrane fuel cell (PEMFC). The prepared via solvothermal-based process, by reacting either cyclo...

Azobenzene (azoB) is a promising anode active material for nonaqueous redox flow battery (NARFB), but the performance assembled with azoB rather poor. Here, we show that rate of NARFB and 2,5-di-tert-butyl-1-methoxy-4-[2?-methoxyethoxy] benzene (DBMMB) as anolyte catholyte materials can be significantly enhanced by optimizing solvent, supporting electrolyte, membrane. The synergistic interactio...

Whey is the major by-product of cheese industry which contains valuable organic materials. Further processes are needed before these materials can be used in food industry. Membrane filtration a convenient alternative to traditional processes. Low energy consumption, reduced processing costs and enhanced quality products main benefits membrane filtration. Due advantages techniques have affected...

Output characteristics of fuel cells are affected by a large number of parameters such as geometry, dimensions, construction materials and conditions of supplying fluids. In this paper a mathematical model followed by a two-dimensional numerical approach has been presented to study the fuel cell parametrically. Effect of oxygen concentration at gas diffusion layer entrance, temperature and ...

Gold nanoparticles were synthesized by chemical reduction of HAuCl4 inside the pores of a polycarbonate-based membrane followed by dissolving the membrane in dichloromethane and further sonication. Sonication time as the main affecting factor on the nanoparticle size was investigated. The characterization by transmission electron microscopy showed the formation of gold nanoparticles with diamet...

background: different methods have been suggested to preserve bone architecture following traumatic events such as teeth extraction. the purpose of the study was to histologically and histomorphometrically evaluate the dental socket healing after applying porous titanium granules (ptg) in dogs. materials and methods: four healthy male dogs were involved in the present 6-weeks experimental anima...

statement of problem: there are limited histomorphometric studies on biologic efficacy of high density tetrafluoroethylen (d-ptfe) membrane. objectives: to investigate the healing of surgically induced grade ii furcation defects in dogs following the use of dense polytetrafluoroethylene as the barrier membrane and to compare the results with the contra lateral control teeth without the applicat...

in this research, process asymmetric polyetherimide hollow fiber membranes using ethanol (0, 2 and 4 wt%) as non-solvent additive in the polymer dope via phase inversion method were fabricated. aqueous solution of 1-methyl-2-pyrrolidine (nmp) (90%) was applied as a bore fluid to avoid inner skin layer formation and water was used as the external coagulant. the morphology of fabricated membranes...