fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

abstract previous researches have shown success of growth hormones usage on flower production increase, pod and prevention of abscission of them in some of the pulses. two tests were done, in order to find out the effects of growth hormones to on flower production increase, pod and chick pea yield composites in farmer conditions (2010-11) and green house conditions as factorial on the proje...

abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate t...

this study examines the effetivenss of task-based activities in helping students learn english language structures for a better communication. initially, a michigan test was administered to the two groups of 52 students majoring in english at the allameh ghotb -e- ravandi university to ensure their homogeneity. the students scores on the grammar part of this test were also regarded as their pre...

in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

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 ...