1,196 research outputs found

    Production of N2 Vegard-Kaplan and other triplet band emissions in the dayglow of Titan

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    Recently the Cassini Ultraviolet Imaging Spectrograph has revealed the presence of N2 Vegard-Kaplan band emissions in Titan's dayglow limb observation. We present model calculations for the production of various N2 triplet states in the upper atmosphere of Titan. The Analytical Yield Spectra technique is used to calculate steady state photoelectron fluxes in Titan's atmosphere, which are in agreement with those observed by the Cassini's CAPS instrument. Considering direct electron impact excitation, inter-state cascading, and quenching effects, the population of different levels of N2 triplet states are calculated under statistical equilibrium. Densities of all vibrational levels of each triplet state and volume production rates for various triplet states are calculated in the model. Vertically integrated overhead intensities for the same date and lighting conditions as the reported by UVIS observations for N2 VK, 1P, 2P, Wu-Benesch, and Reverse First Positive bands of N2 are found to be 132, 114, 19, 22, and 22 R, respectively. Overhead intensities are calculated for each vibrational transition of all the triplet band emissions of N2, which span a wider spectrum of wavelengths from ultraviolet to infrared. The calculated limb intensities of total and prominent transitions of VK band are presented. The model limb intensity of VK emission within the 150-190 nm wavelength region is in good agreement with the Cassini UVIS observed limb profile. An assessment of the impact of solar EUV flux on the N2 triplet band emission intensity has been made by using three different solar flux models, viz., Solar EUV Experiment, SOLAR2000 model of Tobiska (2004), and HEUVAC model of Richards et al, (2006). The calculated N2 VK band intensity at the peak of limb intensity due to S2K and HEUVAC solar flux models is a factor of 1.2 and 0.9, respectively, of that obtained using SEE solar EUV flux.Comment: 25 pages, 11 figures; Icarus, 201

    Production of N2 Vegard-Kaplan and Lyman-Birge-Hopfield emissions on Pluto

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    We have developed a model to calculate the emission intensities of various vibrational transitions of N2_2 triplet band and Lyman-Birge-Hopfield (LBH) band emissions in the dayglow of Pluto for solar minimum, moderate, and maximum conditions. The calculated overhead intensities of Vegard-Kaplan (A3Σu+X1Σg+ A^3\Sigma_u^+ - X^1\Sigma^+_g ), First Positive (B3ΠgA3Σu+ B^3\Pi_g - A^3\Sigma^+_u ), Second Positive (C3ΠuB3Πg C^3\Pi_u - B^3\Pi_g ), Wu-Benesch (W3ΔuB3ΠgW^3\Delta_u - B^3\Pi_g), Reverse First Positive, and LBH (a1Πga^1\Pi_g-- X1Σg+X^1\Sigma^+_g) bands of N2_2 are 17 (74), 14.8 (64), 2.4 (10.8), 2.9 (12.7), 2.9 (12.5), and 2.3 (10) R, respectively, for solar minimum (maximum) condition. We have predicted the overhead and limb intensities of VK (150-190 nm) and LBH (120-190 nm) bands of N2_2 on Pluto for the New Horizons (NH) flyby condition that can be observed by Alice: the ultraviolet imaging spectrograph also know as P-Alice. The predicted limb intensities of VK and LBH bands peak at radial distance of \sim2000 km with the value of about 5 (13) and 9.5 (22) R for solar zenith angle 60 ^\circ (0 ^\circ ), respectively. We have also calculated overhead and limp intensities of few prominent transition of CO Fourth Positive bands for NH flyby condition.Comment: 7 pages, 5 figures, 2 table

    Detection of substrate binding motifs for morphine biosynthetic pathway intermediates in novel wound inducible (R,S)-reticuline 7-O-methyltransferase of Papaver somniferum

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    The benzylisoquinoline alkaloids (BIA) comprise a large and diverse group of nitrogen-containing secondary metabolites with about 2500 compounds identified in plants. BIA biosynthesis begins with the condensation of the tyrosine derived precursors dopamine and p-hydroxyphenylacetaldehyde to (S)-norcoclaurine. Subsequent regiospecific O- and N-methylations and aromatic ring hydroxylation lead to (S)-reticuline, which is the central intermediate for almost all BIAs. For morphinan alkaloid biosynthesis, (S)-reticuline undergoes an inversion of stereochemistry to (R)-reticuline, followed by C-C phenol coupling catalyzed by a unique cytochrome P450-dependent monooxygenase to yield salutaridine. The cDNA sequence of enzymes leading to (S)-reticuline, as well as those involved in the conversion of (R)-reticuline to salutaridine-7-O-acetate are already characterized. The inversion of (S)-reticuline to (R)-reticuline represent the important steps in morphine biosynthesis. Wound induced transcript accumulation in Papaver reveals a novel wound inducible EST (NCBI DbEST: GO238757) showing homology with (R,S)-reticuline 7-O-methyltransferase (ID: Q6WUC2) isolated from Papaver somniferum. We compare the substrate binding homology of this novel wound inducible (R,S)-reticuline 7-O-methyltransferase (7-OMT) using template of P. somniferum (Q6WUC2; gb|AAQ01668) as experimental control. Homology modeling with 70% identity & 85% similarity with catalytic site of template protein i.e., (Q6WUC2) short chain dehydrogenase/reductase (SDR), showed docking energy -69.9 and -75.8 kcal/mol with (S)-Reticuline (CID:439653) and (R)-Reticuline (CID:440586) respectively, which are comparable with experimental control binding site interaction energies. Docking of S- & R-reticuline into the active site revealed eight (F(5), E(18), W(24), C(47), F(44), P(45), C(46) and I(47) amino acids presumably responsible for the high substrate specificity of (R,S)-reticuline 7-O-methyltransferase

    Programming Languages: A Survey

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    The world of Programming Languages is very dynamic. Every company is launching their own programming language which can cater their specific demand and requirement. In this paper, we discussed various popular rankings proposed by different organizations to decide most popular language on basis of various factors like number of Google Trends searches, number of job advertisements, and number of books sold for that language and many more factors

    Impact of solar EUV flux on CO Cameron band and CO2+ UV doublet emissions in the dayglow of Mars

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    This study is aimed at making a calculation about the impact of the two most commonly used solar EUV flux models -- SOLAR2000 (S2K) of \cite{Tobiska04} and EUVAC model of \cite{Richards94} -- on photoelectron fluxes, volume emission rates, ion densities and CO Cameron and CO2+_2^+ UV doublet band dayglow emissions on Mars in three solar activity conditions: minimum, moderate, and maximum. Calculated limb intensities profiles are compared with SPICAM/Mars Express and Mariner observations. Analytical yield spectrum (AYS) approach has been used to calculate photoelectron fluxes in Martian upper atmosphere. Densities of prominent ions and CO molecule in excited triplet a3Π^3\Pi state are calculated using major ion-neutral reactions. Volume emission rates of CO Cameron and CO2+_2^+ UV doublet bands have been calculated for dif{}ferent observations (Viking condition, Mariner and Mars Express SPICAM observations) on Mars. For the low solar activity condition, dayglow intensities calculated using the S2K model are \sim40% higher than those calculated using the EUVAC model. During high solar activity, due to the higher EUV fluxes at wavelengths below 250 \AA\ in the EUVAC model, intensities calculated using EUVAC model are slightly higher (\sim20%) than those calculated using S2K model. Irrespective of the solar activity condition, production of Cameron band due to photodissociative excitation of CO2_2 is around 50% higher when S2K model is used. Altitude of peak limb brightness of CO Cameron and CO2+_2^+ UV doublet band is found to be independent of solar EUV flux models. Calculated limb intensities of CO Cameron and CO2+_2^+ UV doublet bands are on an average a factor of \sim2 and \sim1.5, respectively, higher than the SPICAM Mars Express observation, while they are consistent with the Mariner observations.Comment: 27 Pages, 12 Figures; Planetary and Space Science, 201

    Calculations of N2 triplet states vibrational populations and band emissions in Venusian dayglow

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    A model for N2 triplet states band emissions in the Venusian dayglow has been developed for low and high solar activity conditions. Steady state photoelectron fluxes and volume excitation rates for N2 triplet states have been calculated using the Analytical Yield Spectra (AYS) technique. Model calculated photoelectron flux is in good agreement with Pioneer Venus Orbiter-observed electron flux. Since inter-state cascading is important for the triplet states of N2, populations of different levels of N2 triplet states are calculated under statistical equilibrium considering direct electron impact excitation, and cascading and quenching effects. Densities of all vibrational levels of each triplet state are calculated in the model. Height-integrated overhead intensities of N2 triplet band emissions are calculated, the values for Vegard-Kaplan (A^3Sigma_u^+ - X^1Pi_g^+), First Positive (B^3Pi_g - A^3Sigma_u^+), Second Positive (C^3Pi_u - B^3Pi_g), and Wu-Benesch (W^3Delta_u - B^3Pi_g) bands of N2, are 1.9 (3.2), 3 (6), 0.4 (0.8), and 0.5 (1.1) kR, respectively, for solar minimum (maximum) conditions. The intensities of the three strong Vegard-Kaplan bands (0, 5), (0, 6), and (0, 7) are 94 (160), 120 (204), and 114 (194) R, respectively, for solar minimum (maximum) conditions. Limb profiles are calculated for VK (0, 4), (0, 5), (0, 6) and (0, 7) bands. The calculated intensities on Venus are about a factor 10 higher than those on Mars. The present study provides a motivation for a search of N2 triplet band emissions in the dayglow of Venus.Comment: Icarus, 201

    Tracing Variegated Streaks of Feminism in \u3cem\u3eThe French Lieutenant’s Woman\u3c/em\u3e through Pinteresque Jigsaw

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    Written for screen by one of the greatest English dramatists and Nobel Laureate, Harold Pinter and directed by Karel Reisz, the film The French Lieutenant’s Woman, appearing in 1981, is the cinematic adaptation of John Fowles’ novel by the same name that created ripples in the literary circles in 1969. Keeping in with the appreciation of the novel, the cinematic version of The French Lieutenant’s Woman too continued to capture the imagination of the classes and the masses alike bagging several prestigious awards. The proposed paper intends to study all these variegated shades and designs that further intensify the experimental spirit of the film. Focusing on the movie within the movie that imbues the cinematic adaptation of the novel with a quintessential Pinteresque intensity, the paper explores in depth the subtle nuances offered for intellectual probing through the ingeniously contrived sub-plot. Running as a subtle counterfoil to the main plot of Sarah and Charles, the tempestuous love affair between Mike and Anna—the actors playing Charles and Sarah respectively—the subtext of the movie invites concerted critical endeavors in exploring the intellectual conundrum that confronts us on the silver screen. The paper engages itself in the task of reading through such intellectually stimulating improvisations which subtly reflect the post-modernistic tone and tenor. For this purpose, the paper focuses especially on studying the parallels and proselytes that characterize the protagonists as Sarah and Anna in the main and the sub-plot respectively. The paper also studies the mise-en-scene devices such as light, sound, colours, camera movements, focus, background music, and different types of shots employed in the movie, all of which poetically render the rich contours of the work
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