20,545 research outputs found
Structure and Optical Properties of Polycrystalline InxSb30 – xSe70 (0 ≤ x ≤ 25) Chalcogenide Alloys
The spectroscopic studies of various physical properties of glassy and polycrystalline chalcogenide alloys are important due to their importance as active materials in various solid state devices. The composition dependence of these properties are explained on the basis of coordination number, but the splitting of this effect from the nature of additive is imperative for furthering the understanding of these systems. In the present work, the structural and spectroscopic investigations of melt quenched bulk In-Sb-Se chalcogenide alloys have been studied by XRD, RAMAN and optical spectroscopic techniques. The XRD study reveals the polycrystalline nature of the samples. The composition was analysed using the energy dispersive X-ray spectroscopy technique. The XRD study reveals the crystallization of Sb2Se3 and β-In2Se3 phases while the increase in the intensity for β-In2Se3 phase has been observed with the increase in indium content. The RAMAN spectra also reveal the formation of chalcogenide based Sb and In structural units. The diffused reflectance spectrum was used to calculate the optical absorption in 800-1500 nm spectral region and used to study the composition dependence of the optical gap in these samples. The results have been discussed in conjunction with the heterogeneous phases; density of defect states; electronegativity and average mean bond energy for these polycrystalline alloys
Heterosis for post harvest and nutritional quality traits in tomato (Solanum lycopersicum L.)
A study was conducted in tomato using an 6 x 6 diallel crossing design excluding reciprocals to quantify the magnitude of heterosis and to identify the best heterotic combinations for post harvest and nutritional quality attributes viz. pericarp thickness (mm), fruit firmness (g/0.503 cm2), shelf life (days), total soluble solids (oBrix), lycopene content (mg/100g) and ascorbic acid (mg/100g) which are considered essential in present day hybrid varieties of tomato from consumer point of view. All the 22 entries (6 parents, 15 F1 hybrids and 1 standard check) were field evaluated using randomized complete block design with three replications during Kharif 2015-16. Highly significant heterosis (5% level of significance) of positive nature was found for pericarp thickness (22.90%, 32.20% and 5.62%), fruit firmness (17.32%, 56.72% and 9.21%), shelf life (17.54%, 24.87% and 9.57%), total soluble solids (24.44%, 51.44% and 34.20%), lycopene content (28.75%, 35.05% and 25.63%) and ascorbic acid (19.07%,30.00% and 17.85%) over the better, mid and standard check, respectively. Three promising crosses viz., Solan Lalima x EC-1055, Solan Lalima x EC-1057 and Solan Lalima x EC-1058 were identified as high yielding F1 combinations having superiority to post harvest and nutritional quality traits in tomato and can be promoted for release and commercial cultivation
FUTURISTIC SCOPE OF STEM CELLS IN MEDICINE
ABSTRACTThe most potential application of the stem cells (SCs) in human beings lies in their ability to regenerate cells and tissues. They differentiate themselvesinto specific cell type, thereby availing remarkable source of replacement cells and tissues. They differentiate themselves into specific cell types,thereby availing renewable source of replacement cells and tissues. Their potential of regeneration has now opened many avenues in the field ofmedical science and research. As a therapeutic adjuvant in near future, the SCs will emerge as an efficient technique to completely heal a number ofdiseases including diabetes, heart diseases and strokes, osteoarthritis, rheumatoid arthritis, and macular degeneration. The researches, which areunderway, some of them will surely be proved as safe and effective SC treatment in the market in due course of time.Keywords: Stem cells, Medicine, Embryonic cells, Heart disease
Case Histories of Earthen Dam Failures
Historical study of dams conceived in earlier times is essential. To continue advancing, the engineering profession must periodically review past problems and the lessons that they taught. Candid sharing of information on failures as well as successes is needed. In fact, some of the most valuable learning has come from projects where errors have been clear in retrospect. In recent years, dam safety has drawn increasing attention from the public. This is because floods resulting from breaching of dams can lead to devastating disasters with tremendous loss of life and property, especially in densely populated areas. Past dam failure disasters showed that the loss of life in the event of a dam failure is directly related to the warning time available to evacuate the population at risk downstream of the dam. Earth and rock fill dams are widely used throughout the world, and most of the dam failures involve such dams. To speak about failures of dams without a brief account of these happenings in the dam world is not possible. Therefore, it is essential to go through the case histories of such dam failures to understand the causes of failures of the dams failed in the past. The main causes of failures of such dams are attributed to overtopping, internal erosion and piping. There are excellent sources and case studies are available in the literature related to failure of the earthen dams due to overtopping, internal erosion and piping. The purpose of this paper is to highlight the most promising causes of the earthen dam failures and present the case histories of the dams failed in the world due to these causes. The case histories reported in this paper are chosen not for the entity of the damage occurred, but are representative of the body of knowledge that has been accumulated in the interest of the future safety of dams
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