Growth of carbon nanotubes on quasicrystalline alloys

We report on the synthesis of carbon nanotubes on quasicrystalline alloys. Aligned multiwalled carbon nanotubes (MWNTs) on the conducting faces of decagonal quasicrystals were synthesized using floating catalyst chemical vapor deposition. The alignment of the nanotubes was found perpendicular to the decagonal faces of the quasicrystals. A comparison between the growth and tube quality has also been made between tubes grown on various quasicrystalline and SiO2 substrates. While a significant MWNT growth was observed on decagonal quasicrystalline substrate, there was no significant growth observed on icosahedral quasicrystalline substrate. Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) results show high crystalline nature of the nanotubes. Presence of continuous iron filled core in the nanotubes grown on these substrates was also observed, which is typically not seen in MWNTs grown using similar process on silicon and/or silicon dioxide substrates. The study has important implications for understanding the growth mechanism of MWNTs on conducting substrates which have potential applications as heat sinks

ONE STEP QUANTIFICATION ANALYTICAL METHOD AND CHARACTERIZATION OF VALSARTAN BY LC-MS

Objective: To develop precise LC-MS method for the estimation of valsartan impurities and perform validation as per ICH guidelines.Methods: Valsartan (VLN) and its degradation products were analyzed by reverse phase high-performance liquid chromatography (RP-HPLC) using mobile phase water: acetonitrile: glacial acetic acid: phosphate buffer in the ratio of 500:500:1:0.5 v/v/v/v at 225 nm using column nucleosil C18, 125 ×4.0 mm, 5 µm. VLN sample (VLN SPL) thus obtained an unknown major impurity (UIMP) of 0.5 % at 0.38 retention time ratio (RRt) and purity of VLN was found to be 98.70 % respectively.Results: Estimation of VLN SPL total unknown impurities was found to be 1.3% by RP-HPLC. In similarly by liquid chromatography mass spectroscopy (LC-MS) a typical chromatogram of valsartan (VLN) at Rt 9.03 min and UIMP at Rt 3.3 min were recorded at a total run time of 23 min. Assay of VLN SPL was validated as per international council for harmonization (ICH) guidelines. Average % recovery was found to be 100.04 % for VLN SPL.Conclusion: The proposed work clearly indicates that the method can be easily adapted for the routine one step estimation of VLN active pharmaceutical ingredient (API)

Vacuum storage and seed survival in pearl millet and sorghum

Sorghum (cv. Maldandi) seeds with 8.45% initial moisture content (MC) and 98% germination, and pearl millet (cv. Sadoré local) seeds with 9.2% initial MC and 94% germination were used for the study. The effect of vacuum on seed longevity was studied at three MCs: 6%, 10% and 14%. The MCs were adjusted by holding the seeds on saturated salt solutions of LiCl, MgCl and NaCl for about a week at 25°C. Each seed lot was then subdivided into aliquots of 5 g and hermetically sealed in aluminium foil envelopes containing air or vacuum packed at a pressure of -0.95 bar. Seeds were held at 50°C to accelerate ageing and sampled at regular intervals. The sampling intervals ranged from daily (14% MC) to 8 weeks (6% MC), depending on the storage treatment. In addition to those stored at 50°C some pearl millet seeds were also stored at 35°C. The initial viability of seeds was estimated at the beginning of storage and subsequently at each sampling point by conducting replicated germination tests on fifty seeds. Germination was expressed as the percentage of normal seedlings produced after seven days of incubation at 20°C. There was a gradual loss in germination rate under all storage conditions. Seeds stored under the higher temperature of (50°) and/or high MC (14%) deteriorated faster than with other treatments. Pearl millet seeds survived longer than sorghum under similar conditions of storage. Analysis of variance of the estimates of half-life for the viability of seeds showed significant effects of MC, vacuum packing and their interaction on seed survival at 50°C (P < 0.001). Seeds dried to 6% MC retained viability longer than those stored at 10% and 14% MC. Vacuum packing further enhanced seed longevity at 6% MC but not at 10 or 14% MC

Varietal diallel analysis for yield and yield related traits in fennel (Foeniculum vulgare Mill.)

A half diallel of ni ne genetica lly diverse va rieties was made and resulting 36 Fl populations along with the parents were evaluated during rabi 1997-98. The analysis of variance indicated that heterosis was s ignificant for all the characters, except for branches per plant. The heterosis components were also significant for most of the traits studied. Specific heterosis component accounted for more than 50% of the overall heterosis, indicating complex type of inheritance for seed yield and its component traits. The crosses UP (M)-1 x UF-134, RF-125 x JP-29 and UF-90 x HF-7J exhibited significant and positive heterobeltiosis for seed yield per plant. &nbsp

Liquid Limits: The Glass Transition and Liquid-Gas Spinodal Boundaries of Metastable Liquids

The liquid-gas spinodal and the glass transition define ultimate boundaries beyond which substances cannot exist as (stable or metastable) liquids. The relation between these limits is analyzed {\it via} computer simulations of a model liquid. The results obtained indicate that the liquid - gas spinodal and the glass transition lines intersect at a finite temperature, implying a glass - gas mechanical instability locus at low temperatures. The glass transition lines obtained by thermodynamic and dynamic criteria agree very well with each other.Comment: 5 pages, 4 figures, to appear in Phys. Rev. Let

Astrophysical S_{17}(0) factor from a measurement of d(7Be,8B)n reaction at E_{c.m.} = 4.5 MeV

Angular distribution measurements of $^2$H($^7$Be,$^7$Be)$^2$H and $^2$H($^7$Be,$^8$B)$n$ reactions at $E_{c.m.}\sim$~4.5 MeV were performed to extract the astrophysical $S_{17}(0)$ factor using the asymptotic normalization coefficient (ANC) method. For this purpose a pure, low emittance $^7$Be beam was separated from the primary $^7$Li beam by a recoil mass spectrometer operated in a novel mode. A beam stopper at 0$^{\circ}$ allowed the use of a higher $^7$Be beam intensity. Measurement of the elastic scattering in the entrance channel using kinematic coincidence, facilitated the determination of the optical model parameters needed for the analysis of the transfer data. The present measurement significantly reduces errors in the extracted $^7$Be(p,$\gamma$) cross section using the ANC method. We get $S_{17}$~(0)~=~20.7~$\pm$~2.4 eV~b.Comment: 15 pages including 3 eps figures, one figure removed and discussions updated. Version to appear in Physical Review

Regeneration guidelines: pigeon pea

Pigeonpea (Cajanus cajan (L.) Millsp., syn. Cajanus indicus) is a member of the Fabaceae family and has many wild relatives. These include Cajanus scarabaeoides (L.) Thouars, C. sericeus (Benth. ex Baker) Maesen, C. acutifolius (F. Muell.) Maesen, C. albicans (Wight & Arn.) Maesen, Rhynchosia aurea, R. bracteata Benth. ex Bak and Flemingia bracteata (Roxb.) Wight (van der Maesen 1985). The pigeonpea plant is an erect annual or short-lived perennial reaching a height of 1–3 m. Because the coarse bush is deeply rooted, it has wide adaptability and grows well in semi-arid areas. It has slender, pointed trifoliate leaves and yellow or yellow and red flowers. Pods are green and pointed with some reddish mottling. Several pods are produced in clusters on an upright stem

Regeneration guidelines: pearl millet

Pearl millet (Pennisetum glaucum (L.) R. Br.), also known as bulrush or cattail millet, is an important grain and forage crop in Africa and South Asia and a forage crop in the Americas. It is mostly grown under hot, dry conditions on infertile soils of low water-holding capacity, where other crops generally fail. Pearl millet belongs to the family Poaceae, subfamily Panicoideae, tribe Paniceae, subtribe Panicinae, section Penicillaria and genus Pennisetum. The genus Pennisetum contains about 140 species. The important wild relatives of cultivated pearl millet include the progenitor, Pennisetum glaucum subsp. monodii Maire; P.purpureum K. Schumach.; P. pedicellatum Trin.; P. orientale Rich.; P. mezianum Leeke; and P. squamulatum Fresen................

Thermal Photons in Strong Interactions

A brief survey is given on the current status of evaluating thermal production of photons from a strongly interacting medium. Emphasis is put on recent progress in assessing equilibrium emission rates in both hadronic and quark-gluon matter. We also give an update on the status of comparing theoretical calculations with experimental data from heavy-ion collisions at the SPS, as well as prospects for RHIC. Finally, applications of photon rate calculations to colorsuperconducting quark matter are discussed.Comment: Brief Review for Mod. Phys. Lett A, 15 pages latex incl. 12 ps/eps figs and style file ws-mpla.cl