in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

Enlarged root systems that extend into the salt affected soil improve water and nutrient capture by plants and can increase plant productivity. In order to examine root system characteristics of four bread wheat cultivars contrasting in salt tolerance (Arg, Ofoq, Tajan and Morvarid) a greenhouse experiment was conducted with applying two salinity levels (0 and 150 mM NaCl) on plants grown in PV...

abstract sensitive and precise voltammetric methods for the determination of trace amounts of furaldehydes, mainly as furfural (f) and 5-hydroxymethyl-2-furaldehyde (hmf), in waste waters and other matrices is described. determination of total furaldehyde at < ?g g-1 levels in alkaline buffered aqueous media was individually investigated. by the use of ordinary swv and adsorptive square wave ...

In order to investigate of effect of salinity (NaCl) on soluble sugars and mineral ions concentrations in salt tolerant (IR651) and sensitive (IR29) rice (Oryza sativa L.) genotypes, a factorial based on a completely randomized design was carried out in greenhouse of physiology division of Agricultural Biotechnology Research Institute of Iran (ABRII) in 2006. Seedlings were grown in Youshida nu...

nowadays enhancing critical thinking in learners is considered one of the foreign language teachers’ tasks due to its high position in foreign language classrooms. when it comes to selecting materials for language classrooms, there are obviously some criteria that teachers should apply. the present study aimed at a critical thinking based analysis of ten picture story books and ten folktales th...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

Most researches on wheat and barley breeding for salt tolerance have focused mainly on excluding Na+ from different tissues but the results of some experiments suggest that contribution of Na+ exclusion to salt tolerance is overshadowed by other physiological responses. Three bread wheat cultivars differing in salt tolerance (Arg, Tajan and Baharan) and one barley cultivar (Nik) were employed t...

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...