5,022 research outputs found

    Phytochemical evaluation of Celastrus paniculatus seed oil extracted by a method used by ‘Uraanv’ tribe of Chhattisgarh

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    More than 35,000 plant species are being used in various human cultures around the world for medicinal purposes. Medicated oil plays an important role for prevention and cure of diseases in Ayurveda. Celastrus paniculatus seed oil is such wonderful medicinally useful oil. It is commonly known as Black-Oil tree, Intellect tree, Climbing-staff plant and Jyotishmati and “Tree of life” in Ayurveda. It possesses Anti-depressant, Anti-Parkinson, Anti-Alzheimer’s, Neuroprotective, IQ improving activity. In tribal district (Jashpur) of Chhattisgarh, Indian people uses traditional method to extract C. paniculatus oil. It is commonly used by the tribes for the treatment of various diseases like headache, muscular spasm and local inflammations. The present study aim is documentation of traditional method of oil extraction used by ‘Uraanv’ tribe. This paper also dealt with the Physicochemical and qualitative phytochemical evaluation of C. paniculatus seed oil. Oil yield by traditional method was 25%. Carbohydrate, reducing sugar, monosaccharide, protein, amino acid, steroid, flavonoid, alkaloid, fixed oil, phytosterols, saponin, diterpenoid and cardiac glycoside were found in the oil sample.The GC-MS analysis shows the presence of 47 compounds in the oil. These phytochemical might be responsible for the therapeutic effect of C. paniculatsus seed oil

    Antiferromagnetic Order in Disorder-Induced Insulating Phase of SrRu_{1-x}Mn_xO_3 (0.4<x<0.6)

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    We have performed the powder neutron diffraction measurements on the solid solutions of SrRu_{1-x}Mn_xO_3, and found that the itinerant ferromagnetic order observed in pure SrRuO_3 changes into the C-type antiferromagnetic (AF) order with nearly localized d electrons in the intermediate Mn concentration between x=0.4 and 0.6. With increasing x, the AF moment is strongly enhanced from 1.1 mB (x=0.4) to 2.6 mB (x=0.6), which is accompanied by the elongation of the tetragonal c/a ratio. These results suggest that the substitution of Mn for Ru suppresses the itinerant character of the d electrons, and induces the superexchange interaction through the compression in the c plane. We have also found that the magnetic and transport properties observed in our tetragonal samples are quite similar to those of recently reported orthorhombic ones.Comment: 4 pages, 4 figure

    FT-IR spectroscopic investigation of high sulphur assam coals and their solvent-extracts

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    The FT-IR spectroscopic techniques were used to understand the structural feature of four samples of high sulphur Assam coals and their extracts in polar solvents. Pyridine, N, N-Dimethyl Acetamide and Ethyl Acetate were used for extraction of the coals at their reflux temperatures in a Soxhlet apparatus. The difference-FT-IR spectroscopic technique was used to characterize the compositions of extracts. The extracts were found to contain characteristic absorption bands of original coals. Both aromatic and aliphatic C-H stretching bands were observed in the spectra of extracts. The spectral interpretations of the extracts closely resembled the parent coal structures. The relative transmittances of characteristic bands in extract spectrum suggest that the distribution of functional groups in coals were somewhat effected due to the interaction with the solvents. The spectra show some depletion of bands along with increase in some regions. The information regarding the structure of coal and extracts obtained by this method are qualitative in nature but very much useful in coal utilizations. © Geol. Soc. India

    Strangeness dynamics and transverse pressure in relativistic nucleus-nucleus collisions

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    We investigate hadron production as well as transverse hadron spectra from proton-proton, proton-nucleus and nucleus-nucleus collisions from 2 AA\cdotGeV to 21.3 AA\cdotTeV within two independent transport approaches (HSD and UrQMD) that are based on quark, diquark, string and hadronic degrees of freedom. The comparison to experimental data on transverse mass spectra from pppp, pApA and C+C (or Si+Si) reactions shows the reliability of the transport models for light systems. For central Au+Au (Pb+Pb) collisions at bombarding energies above \sim 5 A\cdotGeV, furthermore, the measured K±K^{\pm} transverse mass spectra have a larger inverse slope parameter than expected from the default calculations. We investigate various scenarios to explore their potential effects on the K±K^\pm spectra. In particular the initial state Cronin effect is found to play a substantial role at top SPS and RHIC energies. However, the maximum in the K+/π+K^+/\pi^+ ratio at 20 to 30 A\cdotGeV is missed by ~40% and the approximately constant slope of the K±K^\pm spectra at SPS energies is not reproduced either. Our systematic analysis suggests that the additional pressure - as expected from lattice QCD calculations at finite quark chemical potential μq\mu_q and temperature TT- should be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions.Comment: 20 pages, 15 figures, Phys. Rev. C, in pres

    The hadron-quark phase transition in dense matter and neutron stars

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    We study the hadron-quark phase transition in the interior of neutron stars (NS's). We calculate the equation of state (EOS) of hadronic matter using the Brueckner-Bethe-Goldstone formalism with realistic two-body and three-body forces, as well as a relativistic mean field model. For quark matter we employ the MIT bag model constraining the bag constant by using the indications coming from the recent experimental results obtained at the CERN SPS on the formation of a quark-gluon plasma. We find necessary to introduce a density dependent bag parameter, and the corresponding consistent thermodynamical formalism. We calculate the structure of NS interiors with the EOS comprising both phases, and we find that the NS maximum masses fall in a relatively narrow interval, 1.4MMmax1.7M1.4 M_\odot \leq M_{\rm max} \leq 1.7 M_\odot. The precise value of the maximum mass turns out to be only weakly correlated with the value of the energy density at the assumed transition point in nearly symmetric nuclear matter.Comment: 25 pages, Revtex4, 16 figures included as postscrip

    Distribution of compact object mergers around galaxies

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    Compact object mergers are one of the currently favored models for the origin of GRBs. The discovery of optical afterglows and identification of the nearest, presumably host, galaxies allows the analysis of the distribution of burst sites with respect to these galaxies. Using a model of stellar binary evolution we synthesize a population of compact binary systems which merge within the Hubble time. We include the kicks in the supernovae explosions and calculate orbits of these binaries in galactic gravitational potentials. We present the resulting distribution of merger sites and discuss the results in the framework of the observed GRB afterglows.Comment: 8 pages, 5 figures, submitted to MNRA

    C2D Spitzer-IRS spectra of disks around T Tauri stars: I. Silicate emission and grain growth

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    Infrared ~5--35 um spectra for 40 solar-mass T Tauri stars and 7 intermediate-mass Herbig Ae stars with circumstellar disks were obtained using the Spitzer Space Telescope as part of the c2d IRS survey. This work complements prior spectroscopic studies of silicate infrared emission from disks, which were focused on intermediate-mass stars, with observations of solar-mass stars limited primarily to the 10 um region. The observed 10 and 20 um silicate feature strengths/shapes are consistent with source-to-source variations in grain size. A large fraction of the features are weak and flat, consistent with um-sized grains indicating fast grain growth (from 0.1--1.0 um in radius). In addition, approximately half of the T Tauri star spectra show crystalline silicate features near 28 and 33 um indicating significant processing when compared to interstellar grains. A few sources show large 10-to-20 um ratios and require even larger grains emitting at 20 um than at 10 um. This size difference may arise from the difference in the depth into the disk probed by the two silicate emission bands in disks where dust settling has occurred. The 10 um feature strength vs. shape trend is not correlated with age or Halpha equivalent width, suggesting that some amount of turbulent mixing and regeneration of small grains is occurring. The strength vs. shape trend is related to spectral type, however, with M stars showing significantly flatter 10 um features (larger grain sizes) than A/B stars. The connection between spectral type and grain size is interpreted in terms of the variation in the silicate emission radius as a function of stellar luminosity, but could also be indicative of other spectral-type dependent factors (e.g, X-rays, UV radiation, stellar/disk winds, etc.).Comment: 17 pages, 13 figures, accepted for publication by ApJ, formatted with emulateapj using revtex4 v4.

    High-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 and WASP-26

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    The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013/) under grant agreement nos. 229517 and 268421. This publication was supported by grants NPRP 09-476-1-078 and NPRP X-019-1-006 from Qatar National Research Fund (a member of Qatar Foundation). TCH acknowledges financial support from the Korea Research Council for Fundamental Science and Technology (KRCF) through the Young Research Scientist Fellowship Programme and is supported by the KASI (Korea Astronomy and Space Science Institute) grant 2012-1-410-02/2013-9-400-00. SG, XW and XF acknowledge the support from NSFC under the grant no. 10873031. The research is supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (grant agreement no. 267864). DR, YD, AE, FF (ARC), OW (FNRS research fellow) and J Surdej acknowledge support from the Communauté française de Belgique – Actions de recherche concertées – Académie Wallonie-Europe.We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 and WASP-26 have been observed with Spitzer, and WASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5–1.2 mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25 arcmin of WASP-26.Publisher PDFPeer reviewe
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