Sciencia Acta Xaveriana

1 - 9

Authors: E. James Jabaseelan Samue,; C. Anu Radha, V. Ramasubramanian

In this work, proton decay from drip line nuclei is discussed, Shanmugam–Kamalaharan model is used which consists of a cubic barrier in the pre scission region connected by a Coulomb plus Yukawa plus exponential potential for the post scission region. Since proton decay transition rates are extremely sensitive to the orbital angular momentum of the proton, a centrifugal barrier is added to the post scission potential. Without any adjustable parameters this model is shown to give proton emissions half lives which are in excellent agreement with the recent experimental data.

23 - 29

Authors: Imran Aziz

The importance of liquid crystals lies in their extensive use in display devises, as well as many other scientific applications. However the use of liquid crystals in different devises depends upon various properties owned by them like order parameter, dielectric constant, dielectric anisotropy, birefringent behaviour, optical transmittance, elastic constants etc. The nematic liquid crystalline state can be described through its positional, orientational order. The orientational order is measure of how the rings and functional groups within a molecule are oriented. In view of applications in the liquid crystal display, it is usually the orientation order parameter S which is most important. Optical anisotropy data used to determine order parameter new nematic liquid crystal 40-cyano-(4-chlorbenzyloxy)- azobenzene by Vuks approach and also its variation with temperature has been discussed. PACS: 61.30.v, 42.70.Df

41 - 50

Authors: J. O. Alicho A. C. Etonihu

Fresh milk samples from ewe, cow, goat, and human of Nigerian stock were analyzed for proximate and heavy metal compositions. The human milk was lowest in crude fat (13.7%) and ash contents (0.61%), but highest in crude protein 4.77%. Goat milk was lowest in moisture (83.3%) and crude protein (3.11%); while cow milk, goat milk, and ewe milk were highest in moisture, crude fat, and ash contents respectively. The levels of Fe (0.21 to 0.51 mg/L), Zn (0.17 to 0.24 mg/L), Cu (0.19 to 0.89 mg/L), and Co (0.01 to 0.06 mg/L) in the samples were acceptable when compared to WHO limits, but higher in their contents of Cr, Mn, and Ni.

59 - 70

Authors: C. Nirmala, P. Nongdam

Orchids represent one of the largest families of angiosperms with innumerable hybrids and varieties producing flowers with high floricultural appeal. Cymbidium eburneum is one of most demanding orchids in international floricultural market because of their highly attractive large showy white flowers with sweet fragrance. However because of extensive exploitation of this orchid for personal gain through illegal collections and deforestation, the population is fast receding from its natural habitat. Proper conservation strategies should be adopted to protect this beautiful plant from extinction. The present study was conducted to establish an efficient regeneration protocol for this important orchid by culturing the immature seeds obtained from green capsules in Mitra and MS medium supplemented with varied combinations of different plant growth hormones. Seed germination was successfully observed in both the culture media incorporated with activated charcoal (AC) in the absence of any growth hormones. Highest seed germination was recorded in NAA supplemented Mitra medium while excellent root proliferation was also found in the same combination when AC wasadded. When BAP was present in association with IBA in both the culture media, germination of seed was very poor with culture growth not observed beyond protocorm stage. However addition of AC alleviated the above problem and seedlings were successfully developed. Maximum leaf formation was found in BAP supplemented media with AC. The seedlings generated were successfully established in the green house after proper hardening. The in vitro protocol so developed from the present study can be utilized for regeneration of this Cymbidium orchid for commercial and conservational purposes.

81 - 83

Authors: V. Siva Rama Prasad, T. Phaneendra

In obtaining a generalization of a result of Das and Naik (1979) for a pair of commuting self-maps on a complete metric space, I.H. Nagaraja Rao and K.P.R. Rao replaced the continuity condition with a new condition. Further they claimed that the latter was weaker than the continuity. In this note we disprove their argument and give a unified version of the results of Das and Naik and of Rao and Rao.