1,167 research outputs found

    Shallow Deep Transitions of Neutral and Charged Donor States in Semiconductor Quantum Dots

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    We carry out a detailed investigation of neutral (D0D^0) and charged (DD^-) impurity states of hydrogen-like donors in spherical semiconductor quantum dots. The investigation is carried out within the effective mass theory (EMT). We take recourse to local density approximation (LDA) and the Harbola-Sahni (HS) schemes for treating many-body effects. We experiment with a variety of confining potentials: square, harmonic and triangular. We observe that the donor level undergoes shallow to deep transition as the dot radius (RR) is reduced. On further reduction of the dot radius it becomes shallow again. We term this non-monotonic behaviour \textbf{SHADES}. This suggests the possibility of carrier {\textbf{\textit{``freeze out''}}} for both D0D^0 and DD^-. Further, our study of the optical gaps also reveals a {\textbf{SHADES}} transition.Comment: 19 pages, 8 figures, Revised Versio

    Financial Performance of PSEs Post-disinvestment

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    India being a developing economy has adopted the concept of mixed economy wherein both the private and public sector were allowed to industrialize the country except few restricted sectors. PSEs controlled by the government played an instrumental role in servicing the country in infrastructure and public services. Since there were lots of political intervention because of which the PSEs derailed from the profit making objective and turned to drainage of wealth which were once referred to be temples of modern India. The PSEs were also suddenly exposed to Global competition which they were not used for operating under protected environment. The level playing field and competition affected the financial performances of PSEs. The paper elucidates the various financial ratios over a period of 10 years and analyzed the performance of the PSEs resurrecting focusing on other factors of their sustainability

    To Scale or Not to Scale : Self-Capacitance, ’’Hubbard U" and Quantum Dot Size ?

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    Design, synthesis and anticonvulsant activity of some new 5,7-dibromoisatin semicarbazone derivatives

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    A series of 5,7-dibromoisatin semicarbazones have been synthesized in good yield, involving aryl urea and aryl semicarbazide formation. The structures of the synthesized compounds were confirmed on the basis of their spectral data. All the compounds were evaluated for anticonvulsant and CNS depressant activities. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) induced seizure method and minimal motor impairment was determined by rotarod test. A computational study was carried out for prediction of pharmacokinetic properties and making them potentially promising agents for the treatment of epilepsy. Compounds (Z)-1-(5,7-dibromo-2-oxoindolin-3-ylidene)-4-(4-chlorophenyl)semicarbazide (DH-05), (Z)-1-(5,7-dibromo-2-oxoindolin-3-ylidene)-4-(3-chloro-4-fluorophenyl)semicarbazide (DH-11) and (Z)-1-(5,7-dibromo-1-methyl-2-oxoindolin-3-ylidene)-4-(3-chloro-4-fluorophenyl)semicarbazide (DH-12) exhibited prominent anticonvulsant effect in the series with little or no neurotoxicity and little CNS depressant effect as compared to standard drug

    Surface Wear Studies in Some Materials Using α-induced Reactions

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    The radio-activity produced during the irradiation of 63,65Cu, 59Co, 93Nb and 121,123Sb targets with α-particles have been measured using activation technique. he yields of radioactive isotopic products 66,67,68 Ga, 61 Cu, 96g,mTc and 123,124,126I have been determined in the energy range ≈ 10-40 MeV using stacked foil Technique. Radioactive counting of samples was performed with a high-resolution gamma-spectrometer. As light ion beams produce an extremely narrow layer of activities in the surface of a material, these reactions may be useful for thin layer activation study

    Different types of mucormycosis: case series

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    Mucormycosis is the third invasive mycosis in order of importance after candidiasis and aspergillosis and is caused by fungi of the class Zygomycetes. The most important species causing Mucormycosis is Rhizopus arrhizus (oryzae). Identification of the agents responsible for mucormycosis is based on macroscopic and microscopic morphological criteria, carbohydrate assimilation and the maximum temperature compatible with its growth. The incidence of mucormycosis is approximately 1.7 cases per 1000 000 inhabitants per year. Clinical diagnosis of mucormycosis is difficult, and is often made at a late stage of the disease or post-mortem. We present here a series of five cases of different types of mucormycosis that were reported in our hospital till date. Of which three patients had good recovery and other two had a fatal outcome. Treatment of mucormycosis requires a rapid diagnosis, correction of predisposing factors, surgical resection or debridement as part of source control-and appropriate anti-fungal therapy. Liposomal amphotericin B is the drug of choice for this condition. The overall rate of mortality of mucormycosis is approximately 40%

    Recent Trends in Breeding of Tropical Grass and Forage Species

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    Germplasm enrichment in major tropical grasses and their characterization for emerging environmental challenges have been major focussed area in the recent past. Breeding efforts in tropical grasses are still limited to few selected species viz. Panicum spp, Cenchrus spp, Pennisetum spp and Bracharia spp and all other grasses use of land races for varietal development through selection have been major source of improvement. The pace of breeding efforts in the tropical grasses have been slowed because of many inherent characteristics viz. apomixis, poor seed set, high photo and thermo sensitivity often creating problem in designing and implementing an effective breeding programme. Identification of sexual lines using the modern tools of biotechnology have given new ways for the improvement in these group of crops. This paper provides overview of the recent development that has taken place in the germplasm collection, utilization and significant achievement made through genomic and biotechnological research

    Integrated effect of bio-organics with chemical fertilizer on growth, yield and quality of cabbage (Brassica oleracea var capitata)

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    This experiment focused on the effects of Pseudomonas fluorescens and humic acid in combination with three different levels of fertilizers on growth, yield and quality traits of Brassica oleracea L. Results indicated that treatments comprising 100% recommended fertilizers package coupled with seedling treated with Pseudomonas fluorescens and humic acid caused significantly higher plant height, dry matter in leaves (head), higher number of non-wrapper leaves and head yield (54.38 tonnes/ha) over 50% recommended dose of fertilizer with Pseudomonas fluorescens applied. Treatment 50% recommended dose of fertilizer applied with Pseudomonas fluorescens and humic acid was at par with 100% recommended dose of fertilizer alone. Total carbohydrate content in head (40.46%) was significantly higher with use of 100% recommended dose of fertilizer with Pseudomonas fluorescens and humic acid. Maximum protein content (18.54%) was noticed with application of 100% recommended dose of fertilizer with Pseudomonas fluorescens and humic acid that was 10.90% higher than recommended dose of fertilizer alone. Fibre content in head was improved remarkably with the use of Pseudomonas fluorescens and humic acid. Significantly higher content of ascorbic acid (34.51 mg/100 g) in head was also registered with application of 100% recommended dose of fertilizer with Pseudomonas fluorescens and humic acid
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