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C21H27NO2, Mr=325.5 , orthorhombic,P21212,, a = 7.516 (2), b = 13.430 (2), c =18.047 (2) A, U= 1821.79 A 3, Z = 4, D x =1.186 Mg m -a, 2(Cu Ka) = 1.5418 A, # = 0.56 mm -1, F(000) = 704, T= 293 K, final R = 0.04 for 1892 reflections with I _> 3a(I). Ring A is planar, and rings B and C adopt a chair conformation. Rings D and E are envelopes, with C(14) and C(17) displaced from their respective planes by 0.643 (3) and 0.482 (3)A. The ring system A/B shows quasi-trans fusion, whilst ring systems B/C and C/D are trans fused about C(8)-C(9) and C(13)-C(14) respectively. The D/E junction shows cis fusion.

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C22H31NO2.H2 O, M r = 359" 5, orthorhombic,P2~212 ~, a= 10.032 (1), b= 11.186 (1), C = 17.980 (1)/~,, U= 2017.48/~3, Z = 4, D x = 1.276 Mg m -a, 2(Cu Kct) = 1.5418/~, # = 0.69 mm -~,F(000) = 784, T = 293 K. Final R = 0.05 for 1972 unique reflections with I > 3o(/). Ring A is planar, and rings B and C adopt a chair conformation. Rings D and E are envelopes, with C(14) and C(20) displaced from their respective ring planes by 0-616 (2) and 0.648 (3)/~. The A/B ring junction is quasi-trans,whilst ring systems B/C and C/D are trans fused about the bonds C(8)-C(9) and C(13)-C(14) respectively.The D/E junction shows cis fusion.

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This paper is concerned with a study of an operator split scheme and unsplit scheme for the computation of adiabatic freely propagating one-dimensional premixed flames. The study uses unsteady method for both split and unsplit schemes employing implicit chemistry and explicit diffusion, a combination which is stable and convergent. Solution scheme is not sensitive to the initial starting estimate and provides steady state even with straight line profiles (far from steady state) in small number of time steps. Two systems H2-Air and H2-NO (involving complex nitrogen chemistry) are considered in presentinvestigation. Careful comparison shows that the operator split approach is slightly superior than the unsplit when chemistry becomes complex. Comparison of computational times with those of existing steady and unsteady methods seems to suggest that the method employing implicit-explicit algorithm is very efficient and robust.

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We study charge pumping when a combination of static potentials and potentials oscillating with a time period T is applied in a one-dimensional system of noninteracting electrons. We consider both an infinite system using the Dirac equation in the continuum approximation and a periodic ring with a finite number of sites using the tight-binding model. The infinite system is taken to be coupled to reservoirs on the two sides which are at the same chemical potential and temperature. We consider a model in which oscillating potentials help the electrons to access a transmission resonance produced by the static potentials and show that nonadiabatic pumping violates the simple sin phi rule which is obeyed by adiabatic two-site pumping. For the ring, we do not introduce any reservoirs, and we present a method for calculating the current averaged over an infinite time using the time evolution operator U(T) assuming a purely Hamiltonian evolution. We analytically show that the averaged current is zero if the Hamiltonian is real and time-reversal invariant. Numerical studies indicate another interesting result, namely, that the integrated current is zero for any time dependence of the potential if it is applied to only one site. Finally we study the effects of pumping at two sites on a ring at resonant and nonresonant frequencies, and show that the pumped current has different dependences on the pumping amplitude in the two cases.

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A spin one XY ferromagnet with uniaxial anisotropy has been investigated, using Green's function technique in random phase approximation (RPA). The Green functions associated with the anisotropy energy are treated without decoupling. A set of coupled equations have been obtained to find the critical temperature Tc and left angle bracket(SZ)2right-pointing angle bracket at Tc as function of the uniaxial anisotropy parameter D. Tc and left angle bracket(SZ)2right-pointing angle bracket at Tc are found to increase with D. The results are compared with the earlier results obtained in the Narath type of RPA.

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The use of electroacoustic analogies suggests that a source of acoustical energy (such as an engine, compressor, blower, turbine, loudspeaker, etc.) can be characterized by an acoustic source pressure ps and internal source impedance Zs, analogous to the open-circuit voltage and internal impedance of an electrical source. The present paper shows analytically that the source characteristics evaluated by means of the indirect methods are independent of the loads selected; that is, the evaluated values of ps and Zs are unique, and that the results of the different methods (including the direct method) are identical. In addition, general relations have been derived here for the transfer of source characteristics from one station to another station across one or more acoustical elements, and also for combining several sources into a single equivalent source. Finally, all the conclusions are extended to the case of a uniformly moving medium, incorporating the convective as well as dissipative effects of the mean flow.

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Contrary to that of phenyl derivative 1 the radical 4 adds to radicophiles in an inter- followed by intra-molecular radical Michael addition (radical annulation), furnishing a novel route to chiral isotwistanes 5.

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Nucleotide pyrophosphatase of mung bean seedlings has earlier been isolated in our laboratory in a dimeric form (Mr 65,000) and has been shown to be converted to a tetramer by AMP and to a monomer by p-hydroxymercuribenzoate. All the molecular forms were enzymatically active with different kinetic properties. By a modified procedure using blue-Sepharose affinity chromatography, we have now obtained a dimeric form of the enzyme which is desensitized to AMP interaction. The molecular weight of the desensitized form of the enzyme was found to be the same as that of the native dimeric enzyme. However, the desensitized enzyme functioned with a linear time course, contrary to the biphasic time course exhibited by the native enzyme. In addition, it was not converted to a tetramer on the addition of AMP, had only one binding site for adenine nucleotides, and p-hydroxy-mercuribenzoate had no effect on the time course of the reaction or on the molecular weight of the enzyme. The temperature optimum of the desensitized enzyme was found to be 67 °C in contrast to the optimum of 49 °C for the native dimer. Fifty percent of the tryptophan residues of the desensitized enzyme were not accessible for quenching by iodide. Fluorescence studies gave Kd values of 0.34, 2.2, and 0.8 mImage for AMP, ADP, and ATP, which were close to the Ki values of 0.12, 2.2, and 0.9 mImage , respectively, for these nucleotides. The binding and inhibition studies with AMP and its analogs showed that the 6-amino group and the 5′-phosphate group were essential for the inhibition of the enzyme activity.

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Reaction of 6-Image -butyl-1-bromomethyl-2-(2-tetrahydropyranyloxy)-naphthalene2c with tetrachlorocatechol (TCC) in acetone in presence of K2CO3 gave diastereomers 6c and 7c. A mechanism (Scheme-1) invoking the base induced cleavage of the pyranyl ether 2 to 1,2-naphthoquinone-1-methide 8 as the first step has been postulated. The cleavage of the pyranyl ether linkage in 2 to give dimers 4 and 5 of 1,2-naphthoquinone-1-methide has been demonstrated with different bases. 1,2-Naphthoquinone-1-methide 8, thus generated, undergoes Michael addition with TCC followed by elimination of chloride ions to give a diketone, which further undergoes aldolisation with acetone to give diastereomers 6 and 7. Michael reaction of 8, generated Image from pyranyl ethers 2a-c, with tetrabromocatechol (TBC) under similar-reaction conditions gave the expected monobromo compounds 6h, 6i, 6k, 7n, 7n and 7q. The last step in the proposed mechanism, Image ., aldolisation has also been demonstrated using different ketonic solvents. Thus, reaction of 2a-c with TCC/TBC in diethyl ketone/methyl ethyl ketone under similar reaction conditions gave the expected compounds 6 and 7.

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Methanolic hydrogen chloride cyclization of the triketone 8, prepared from the Mannich base 7 and 2-methylcyclopentane-1,3-dione, gives ketones 9 and 10. NaBH4 reduction of 9 followed by Grignard reaction with CH3MgI affords the diol 12. Catalytic hydrogenation of 12 followed by PCC oxidation yields the ketoalcohol 13. Dehydration of 13 with SOCl2/pyridine results in a 1:1 mixture of the endo-14 and exo-15 olefins, separated by chromatography.

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The microorganism Mucor piriformis transforms androst-4-ene-3,17-dione into a major and several minor metabolites. X-ray crystallographic analysis of two of these metabolites was undertaken to determine unambiguously their composition and chirality. Crystals belong to the orthorhombic space-group P2(1)2(1)2(1), with a = 7.199(4) angstrom and a = 6.023(3) angstrom, b = 11.719(3) angstrom and b = 13.455(4) angstrom, c = 20.409(3) angstrom and c = 20.702(4) angstrom for the two title compounds, respectively. The structures have been refined to final R values of 0.060 and 0.040, respectively.

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This is a study on the changing practices of kinship in Northern India. The change in kinship arrangements, and particularly in intermarriage processes, is traced by analysing the reception of Hindi popular cinema. Films and their role and meaning in people´s lives in India was the object of my research. Films also provided me with a methodology for approaching my other subject-matters: family, marriage and love. Through my discussion of cultural change, the persistence of family as a core value and locus of identity, and the movie discourses depicting this dialogue, I have looked for a possibility of compromise and reconciliation in an Indian context. As the primary form of Indian public culture, cinema has the ability to take part in discourses about Indian identity and cultural change, and alleviate the conflicts that emerge within these discourses. Hindi popular films do this, I argue, by incorporating different familiar cultural narratives in a resourceful way, thus creating something new out of the old elements. The final word, however, is the one of the spectator. The “new” must come from within the culture. The Indian modernity must be imaginable and distinctively Indian. The social imagination is not a “Wild West” where new ideas enter the void and start living a life of their own. The way the young women in Dehra Dun interpreted family dramas and romantic movies highlights the importance of family and continuity in kinship arrangements. The institution of arranged marriage has changed its appearance and gained new alternative modes such as love cum arranged marriage. It nevertheless remains arranged by the parents. In my thesis I have offered a social description of a cultural reality in which movies act as a built-in part. Movies do not work as a distinct realm, but instead intertwine with the social realities of people as a part of a continuum. The social imagination is rooted in the everyday realities of people, as are the movies, in an ontological and categorical sense. According to my research, the links between imagination and social life were not so much what Arjun Appadurai would call global and deterritorialised, but instead local and conventional.