No abstract

No abstract

Gallium oxide target was irradiated with 46 MeV alpha-particle beam, which produced 71,72As and 67Ga radioisotopes in the matrix. Separation of radio-arsenics from the bulk gallium target was carried out by caffeine, a nature-resourced reagent, extracted from black tea leaves. 71,72As radionuclides were preferentially attached with caffeine and precipitated with caffeine in 2 M Na2SO4 solution as caffeine was insoluble in aqueous medium under this condition. With increase in weight of caffeine, extraction of 71,72As and bulk gallium significantly increased. Bulk Ga along with 67Ga remained in the supernatant. Geometry optimization of caffeine–metal complex was carried out by theoretical computational analysis. DFT calculation corroborated with the experimental findings where As3+ preferentially binds with caffeine in presence of gallium and arsenic. As evidenced by the short As–O and As–N distances, the high binding energies are a result of the metal ion’s strong binding to the carbonyl and nitrogen centres, whereas no such result could be obtained in case of bulk gallium.

No abstract

Design and architectures of new 11:2 decimal compressors have been reported in this paper. Two design methodologies viz. delay and area optimized compressors have been introduced and implemented through tree structure of decimal number system. The architectures have been realized through vertical carry save addition algorithm, wherein to build up such addition of unconventional (4221 and 5211) binary coded decimal technique has been incorporated. Configurations of such compressors have been prototyped and transistor level implementation have been carried out to evaluate performance parameters like speed (propagation delay), power dissipation, area and area delay product. The architecture has been validated by Cadence virtuoso platform using 90 nm, 65 nm and 45 nm CMOS technology which provides useful statistics to determine the compressor's performance parameters. The propagation delay of the delay optimized compressor equals to *0.094 ns while the propagation delay of the area optimized compressor is *0.124 ns using 90 nm CMOS technology at 1 V supply voltage. The reported architectures are *24% and *41% faster from its counterpart. adhana(0123456789().,-volV)FT3 ](0123456789().,-volV)