995 resultados para Nuclear reactions.


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Li n.m.r, in single crystals of lithium acetate dihydrate is used to determine the quadrupole coupling parameters: (e2qQ/h) and r/. The orientations of the principal z, y and x components of the electric field gradient tensor are determined to be along the crystallographic b, a and c axes respectively. The parameters experimentally determined are (e2qQ/h)= 154"6 kHz; and i/= 0.9. This study indicates a tetrahedral configuration around the Li ion, confirming the recent X-ray and p.m.r, results.

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Pure thiophosphoryl fluoride has been prepared by the fluorination of thiophosphoryl chloride by sodium fluoride in acetonitrile medium. Oxidation of this phosphoryl fluoride by acidified chloramine-T ruptures the phosphorus-sulphur bond and oxidises the sulphur present to the hexavalent state. Anhydrous hydrogen iodide reduces the sulphur to hydrogen sulphide and phosphorus to the trivalent state.

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A cDNA library for 6S–9S poly(A)-containing RNA from rat liver was constructed in Image . Initial screening of the clones was carried out using single stranded 32P-labeled cDNA prepared against poly(A)-containing RNA isolated from immunoadsorbed polyribosomes enriched for the nuclear-coded subunit messenger RNAs of cytochrome c oxidase. One of the clones, pCO89, was found to hybridize with the messenger RNA for subunit VIC. The DNA sequence of the insert in pCO89 was carried out and it has got extensive homology with the C-terminal 33 amino acids of subunit VIC from beef heart cytochrome c oxidase. In addition, the insert contained 146 bp, corresponding to a portion of the 3′-non-coding region. Northern blot analysis of rat liver RNA with the nick-translated insert of pCO89 revealed that the messenger RNA for subunit VI would contain around 510 bases.

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By using the same current-time (I-t) curves, electrochemical kinetic parameters are determined by two methods, (a) using the ratio of current at a given potential to the diffusion-controlled limiting current and (b) curve fitting method, for the reduction of Cu(II)–CyDTA complex. The analysis by the method (a) shows that the rate determining step involves only one electron although the overall reduction of the complex involves two electrons suggesting thereby the stepwise reduction of the complex. The nature of I-t curves suggests the adsorption of intermediate species at the electrode surface. Under these circumstances more reliable kinetic parameters can be obtained by the method (a) compared to that of (b). Similar observations are found in the case of reduction of Cu(II)–EDTA complex.

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A versatile and flexible digital pulse programmer for two-pulse, three-pulse, saturation burst and Carr-Purcell sequences is described. Independently variable controls for pulse widths (0.2 mu s to 100 mu s), delay between pulses (0.2 mu s to 100 s) and for number of pulses (1 to 99) for the saturation burst and for the Carr-Purcell sequence, are brought to the front panel. The programmer can be used for one-shot experiments as well as for repetitive experiments.

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This thesis examines the interrelationship and dynamics between the Indian United Progressive Alliance government’s foreign policy and its nuclear weapons policy. The purpose of the study is to situate nuclear policy within a foreign policy framework, and the fundamental research problem is thus how does the Indian nuclear policy reflect and respond to the Indian foreign policy? The study examines the intentions in the Indian foreign and nuclear policies, and asks whether these intentions are commensurable or incommensurable. Moreover, the thesis asks whether the UPA government differs from its predecessors, most notably the Bharatiya Janata Party-led National Democratic Alliance government in its foreign and nuclear policies. Answers to these questions are based on the interpretation of political texts and speeches as suggested by Quentin Skinner’s notion of meaning3, what does a writer or speaker mean by what he or she says in a given text, and by J.L. Austin’s speech act theory. This linguistic perspective and the approach of intertextualizing, place the political acts within their contingent intellectual and political contexts. The notion of strategic culture is therefore introduced to provide context for these juxtapositions. The thesis firstly analyses the societal, historical and intellectual context of India’s foreign and nuclear policy. Following from this analysis the thesis then examines the foreign and nuclear policies of Prime Minister Manmo-han Singh’s UPA government. This analysis focuses on the texts, speeches and statements of Indian authorities between 2004 and 2008. This study forwards the following claims: firstly, the UPA Government conducts a foreign policy that is mainly and explicitly inclusive, open and enhancing, and it conducts a nuclear policy that is mainly and implicitly excluding, closed and protective. Secondly, despite the fact that the notion of military security is widely appreciated and does not, as such, necessarily collide with foreign policy, the UPA Government conducts a nuclear policy that is incommensurable with its foreign policy. Thirdly, the UPA Gov-ernment foreign and nuclear policies are, nevertheless, commensurable re-garding their internal intentions. Finally, the UPA Government is conduct-ing a nuclear policy that is gradually leading India towards having a triad of nuclear weapons with various platforms and device designs and a function-ing and robust command and control system encompassing political and military planning, decision-making and execution. Regarding the question of the possible differences between the UPA and NDA governments this thesis claims that, despite their different ideological roots and orientations in domestic affairs, the Indian National Congress Party conducts, perhaps surprisingly, quite a similar foreign and nuclear policy to the Bharatiya Janata Party.

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THE COMPLEXES of pyridine-l-oxide and 2- and 4-substituted pyridine-l-oxides have been investigated previously[l]. The complexes of 3-substituted pyfidine-l-oxides, however, have received little attention. The rare-earth complexes of pyridine-Ioxide[l, 2], 4-methylpyridine- l-oxide [1] and 2,6- dimethylpyfidine-l-oxide[3,4] have been reported earlier. The present paper deals with the isolation and characterisation of 3-methylpyridine-l-oxide (3-Picoline-N-oxide, 3-PicNO) complexes with rare-earth perchlorates.

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The porphyrogenic drug allylisopropylacetamide, a potent inducer of delta-aminolaevulinate synthetase, specifically increases nucleoplasmic RNA synthesis in rat liver. The drug-mediated increase in nucleoplasmic RNA synthesis is blocked by cycloheximide and haemin, which also inhibit the enzyme induction.

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The effect of phenobarbital on the rates of the synthesis of the protein and heme moieties of cytochrome P-450 has been studied. For this purpose, cytochrome P-450 has been partially purified as its P-420 derivative and the labeled amino acid incorporation into the protein has been studied after subjecting a partially purified preparation to sodium dodecyl sulfate gel electrophoresis. The incorporation studies into the protein species after sodium dodecyl sulfate gel electrophoresis reveal that the drug primarily accelerates the rate of apoprotein synthesis followed by an increase in the rate of heme synthesis. The messenger for apocytochrome P-450 appears to be fairly stable.

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The reaction of octachlorocyclotetraphosphazatetraene, N4P4Cl8, with ethylamine has been investigated. Seven derivatives, N4P4Cl8–n(NHEt)n[n= 1, 2 (two isomers), 3, 4 (two isomers), and 8] have been isolated and their structures established by 1H and 31P n.m.r. spectroscopy. A non-geminal chlorine atom replacement scheme is observed. Attempts to prepare penta- or hexa-ethylamino derivatives were unsuccessful: only sticky, non-crystalline resins were obtained from 1 : 10 or 1 : 12 reactions. The preparation and n.m.r. spectroscopic data of mixed ethylamino(methoxy)-derivatives. N4P4(NHEt)–8-n(OMe)n[n= 6, 4 (two isomers)], and an ethylamino-(dimethylamino)-derivative, N4P4(NHEt)2(NMe2)6, are generally consistent with the proposed structures. The reaction pattern is discussed.

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Abstract is not available.

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Abstract is not available.