R. Dubey

Decoupling the effect of temperature on GDR widths in excited compound nucleus 144Sm

We measured giant dipole resonance (GDR) γ-rays in the 28Si + 116Cd reaction at ~105 and 120 MeV excitation energies. The resonance widths were extracted as a function of temperature at different angular momentum values to decouple the effect of these two variables on resonance widths. The high energy GDR γ-rays from the decay of compound nucleus (CN) 144Sm were measured using a large NaI(Tl) detector in coincidence with a sum-spin multiplicity filter. The experimental data were analyzed under the framework of statistical decay of CN. The GDR cross sections were also calculated with a thermal shape fluctuation model (TSFM), which incorporates the temperature and spin dependent shell corrections within the Nilsson–Strutinsky approach. The GDR widths were extracted in the temperature range 1.5–2.2 MeV. The measured widths indicate that the increase of GDR widths with temperature at different average spin values follows a similar trend and is borne out by theoretical calculations. Present calculation shows that TSFM satisfactorily reproduces the GDR cross section as well as widths in the temperature range 1–2.2 MeV over a wide range of angular momentum.

Combining ability analysis for grain yield and its contributing traits in maize (Zea mays L.) over environments

Combining ability analysis for grain yield and its contributing traits in maize was performed with 15 inbred line and 3 tester parents and the resulting 45 hybrids using line x tester cross analysis in three environments during kharif and rabi 2014. The results of combining ability analysis over the environments revealed significant mean squares due to general and specific combining ability indicating that both additive and non-additive gene actions were important in the inheritance of characters studied. The parents L2 (EIQ -132), L4(EIQ-134), L5(EIQ-135), L6(EIQ-136), L8(EIQ-138), and L14(EIQ-144) and L15 (EIQ145) were good general combiners for grain yield and majority of traits over the environments. Hence, these parents can be used in crossing and further exploited for improvement of traits in the population. Six inbred lines viz., L1(EIQ-131), L2(EIQ 132), L3(EIQ-133), L6(EIQ-136), L8(EIQ-138) and L14(EIQ-144) were identified good general combiner for maturity related traits. Whereas the crosses L7 x T2 (EIQ-137 x EIQ-102), L13 x T3 (EIQ-143 x EIQ-103), L10 x T1 (EIQ-140 x EIQ-101), L1 x T1(EIQ-131 x EIQ-101) and L11 x T3 (EIQ-141 x EIQ-103) were identified as potential ones for yield and yield components based on high sca effects along with high per se performance. These hybrids may be exploited for commercial cultivation by testing them over locations and years for their yield stability.