270 research outputs found

    Trisomics in pearl millet, Pennisetum glaucum(L.) R.Br.: development and morphological variation

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    Crosses between autotetraploid and diploid lines of Pennisetum glaucum (L.) R.Br. resulted in triploids. Progeny were obtained by selfing of F1 triploids and/or backcrossing with diploid parent. Trisomic progeny were classified into seven groups based on their morphological characters. Seed-set was poor on trisomics (10-15%). Transmission rates of the disomic (x + 1) gametes of different trisomics were high, ranging from 16.7%-60.7% although seed germination was poor (6.8%). The progeny of each trisomic exhibited considerable morphological variation due to the heterogeneity resulting from differences in the genetic background of the parental accessions used unlike the uniformity found in earlier studies, where the autotetraploid parents were derived from the corresponding diploid parents

    DBD Plasma Assisted CO2 Decomposition: Influence of Diluent Gases

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    arbon dioxide (CO2) partial reduction to carbon monoxide (CO) and oxygen has been conducted in a dielectric barrier discharge reactor (DBD) operating a packed bed configuration and the results are compared with that of no packing condition. The effect of diluent gas is studied to understand the influence on dielectric strength of the plasma gas on CO2 splitting, with the objective of obtaining the best CO selectivity and high energy efficiency. Typical results indicated that among N-2, He and Ar gases, Ar showed the best decomposition efficiency. Glass beads packing has a strong influence on the performance, probably due to the enhanced field strength due to dielectric nature of the packed material. In a similar manner, Ar mole ratio in the gas mixture also played a significant role, where the maximum CO2 conversion of 19.5% was obtained with packed DBD at CO2: Ar ratio 1: 2. The best CO yield (16.8%) was also obtained under the same conditions. The highest energy efficiency was found to be 0.945 mmol/kJ. The activated species formed inside the CO2 plasma were identified by optical emission spectroscopy

    Telangana: Researchers unleash their creative streak

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    To encourage creativity among students and researchers, and present their scientific findings through artistic images, Creative & Advanced Research Based On Nanomaterials (CARBON) Lab in association with Indian National Young Academy of Science (INYAS) organised SciArt, the first Intra-IIT exhibition-cum-competition at Indian Institute of Technology-Hyderabad (IIT-H)

    Esterification of methacrylic acid with ethylene glycol over heteropolyacid supported on ZSM-5

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    Esterification of methacrylic acid with ethylene glycol was carried out over Heteropolyacids [HPA: H4SiW12O40 (STA) and H3PW12O40 (PTA)] supported on ZSM-5. For comparison, the same reaction was carried out over unsupported HPA, H 2SO4, BF3 and PTSA. Among the catalysts studied, HPA showed better activity compared to H2SO4, BF3 and PTSA. Catalytic activity was compared with HPA supported ZSM-5 catalysts. Typical results indicated that 30 wt% PTA supported on ZSM-5 showed nearly the same activity as that of bulk PTA. It was found that the reaction follows first order kinetics with respect to methacrylic acid. The reaction products were identified by 1H-NMR and FT-IR

    Novel Catalytic Dielectric Barrier Discharge Reactor for Gas-Phase Abatement of Isopropanol

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    Catalytic gas-phase abatement of air containing 250ppm of isopropanol (IPA) was carried out with a novel dielectric barrier discharge (DBD) reactor with the inner catalytic electrode made of sintered metal fibers (SMF). The optimization of the reactor performance was carried out by varying the voltage from 12.5 to 22.5kV and the frequency in the range 200-275Hz. The performance was significantly improved by modifying SMF with Mn and Co oxide. Under the experimental conditions used, the MnO x /SMF showed a higher activity towards total oxidation of IPA as compared to CoO x /SMF and SMF electrodes. The complete destruction of 250ppm of IPA was attained with a specific input energy of ∼235J/L using the MnO x /SMF catalytic electrode, whereas, the total oxidation was achieved at 760J/L. The better performance of the MnO x /SMF compared to other catalytic electrodes suggests the formation of short-lived active species on its surface by the in-situ decomposition of ozon

    Kinetics of hydrogen sulfide decomposition in a DBD plasma reactor operated at high temperature

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    The present study investigates the kinetics of hydrogen sulfide (H 2 S) decomposition into hydrogen and sulfur carried out in a nonthermal plasma dielectric barrier discharge (NTP-DBD) reactor operated at ∼ 430 K for in situ removal of sulfur condensed inside the reactor walls. The dissociation of H 2 S was primarily initiated by the excitation of carrier gas (Ar) through electron collisions which appeared to be the rate determining step. The experiments were carried out with initial concentration of H 2 S varied between 5 and 25 vol% at 150 mL/min (at standard temperature and pressure) flow rate in the input power range of 0.5 to 2 W. The reaction rate model based on continuous stirred tank reactor (CSTR) model failed to explain the global kinetics of H 2 S decomposition, probably due to the multiple complex reactions involved in H 2 S decomposition, whereas Michaelis-Menten model was satisfactory. Typical results indicated that the reaction order approached zero with increasing inlet concentration

    Enhanced photocatalytic and antibacterial activity of plasma-reduced silver nanoparticles

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    A non-thermal atmospheric pressure plasma jet has been used for the green synthesis of highly dispersed colloidal silver nanoparticles. The reducing species such as hydrogen radicals and hydrated electrons are identified, and the change in the solution pH is studied during AgNP formation. The structural properties and size of the plasma-reduced silver nanoparticles are characterized via X-ray diffraction, ultraviolet-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The size of the colloidal AgNPs is tuned by adjusting the initial concentration of AgNO3. The effect of terephthalic acid, a hydroxyl radical scavenger, on the reduction of Ag+ ion is studied. The typical catalytic activity data indicate the better performance of the plasma-reduced colloidal Ag nanoparticles than that obtained from the chemical reduction method. The antibacterial activity of the plasma-reduced Ag nanoparticles also shows a better performance than that of the chemically reduced AgNPs, highlighting the potential of the plasma reduction approach for the synthesis of metal nanoparticles, which are stable even after 30 days without a stabilizing agent. Additionally, the effects of hydroxyl scavengers (isopropyl alcohol) and Fenton's reagent (Fe2+ salt) on CV degradation are studied

    Performance Analysis of No Reference Image quality based on Human Perception

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    In this work, a No-Reference objective image quality assessment based on NRDPF-IQA metric and classification based metric are tested using LIVE database, which consisting of Gaussian white noise, Gaussian blur, Rayleigh fast fading channel, JPEG compressed images, JPEG2000 images. We plot the Spearman’s Rank Order Correlation Coefficient [SROCC] between each of these features and human DMOS from the LIVE-IQA database using our proposed method to ascertain how well the features correlate with human judgement quality. The analysis of the testing and training is done by SVM model. The proposed method shows better results compared with the earlier methods. Finally, the results are generated by using MATLAB.DOI:http://dx.doi.org/10.11591/ijece.v4i6.678
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