the extraction-separation of lanthanum and europium ions with bis(2-ethylhexyl) phosphoric acid (dehpa) in cyclohexane was improved by adding 12-crown-4 (12c4) to the aqueous phase as a masking agent. in the presence of this crown ether the extraction curve of lanthanum ions versus ph shifts to the higher ph region, while the curve is not influenced for the europium ions. consequently the separ...

o b e c o m e f u l l y l i t e r a t e i n t o d a y ’ s world, students must become proficient i n t h e n e w l i t e r a c i e s o f 2 1 s t c e n t u ry technologies. As a result, literacy e d u c a t o r s h a v e a r e s p o n s i b i l i t y t o e f f e c tively integrate these new technologies i n t o t h e c u r r i c u l u m , p r e p a r i n g s t u d e n t s for...

in the fifth development plan establishment, establishment of the cadastre system of agriculture nationwide has been defined to be the work priority of institutions and organizations responsible in the area of agriculture and equity issuance in the country. in this study, the possibility of provision of the cadastral mapping of agriculture by a integration of the data of the remote sensing and ...

introduction todays, the application of new methods for monitoring and online management of agricultural farms is necessary to increase quality and quantity of agricultural products. remote sensing is one of the technologies that can be used to monitor agricultural farms and natural resources. this technology is capable of detection and prediction of farm changes by application of satellite and...

R e s u l t s o f p r e l i m i n a r y t e s t s t o measure i c e g r o w t h on an a i r f o i l d u r i n g f l i g h t i c i n g c o n d i t i o n s a r e p resen ted . U l t r a s o n i c pu lse-echo measurements o f i c e t h i c k n e s s a r e o b t a i n e d f rom an a r r a y o f e i g h t u l t r a s o n i c t r a n s d u c e r s mounted f l u s h w i t h t h e l e a d i n g edge o ...

effects of different k/ca ratios on the growth, yield and physiological characteristics in galia (cucumis melo var. reticulatus l. naud. cv. galia) grown in hydroponics were evaluated. the experiment was arranged in a completely randomized design of three replicates. melon seeds were sown in a medium containing perlite and vermiculite (3:1 v:v) and then irrigated with water containing different...

in order to evaluate efficiency of nitrogen fertilizers consumption in a sugar beet monogerm hybrid variety of zarghan, a field experiment was conducted in a loamy soil during 2007 in the research farm of sugar beet seed institute located in karaj. five levels of nitrogen fertilizers including 0 (check), 120, 160, 200 and 240 kg/ha of net nitrogen from urea fertilizer (46 percent of pure nitrog...

sexual behavior in most moths is limited to a precise duration period of either the day or the night. these behaviors as well as the calling behavior are specific. information on reproductive behavior is important in the chemical ecology studies. experiments were conducted to determine the developmental biology, adult time emergence and calling behaviors of three populations of carob moth, ecto...

in order to study the effect of different levels of nitrogen and sulfur fertilizers on yield, yield components, content of some elements, qualitative and quantitative traits of spring safflower (serin cv.) an experiment was conducted at agriculture and natural resource research station of ardabil in 2008. this experiment was carried out in factorial experiment in completely randomized block des...