215 research outputs found

    Studies on physico-chemical constituents in different cultivars of citrus fruits under Lucknow condition, India

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    The physico-chemical studies were conducted on the citrus fruits of sweet orange cv. Mosambi Local-1, 2, 3, 4 and 5 and Sweet Mandarin cv. Chinese Orange, Kinnow, Nagpur Mandarin, Local Mandarin-1 and Local Mandarin- 2. The Sweet Orange cultivar was highest size in Mosambi Local-3 with maximum fruit volume 204 ml and flesh weight 139.66 g followed by Mosambi Local-4. The juice recovery percent was maximum in Mosambi Local-3 28.63 and the highest specific gravity was found in Mosambi Local-1 (0.99) followed by Mosambi Local-2 (0.94). The different cultivars of Sweet Orange were recorded varies from the total soluble solid 7.60 to 12.66 percent, reducing sugar 4.13 to 7.08 per cent, total sugar 5.90 to 10.12 per cent, tritrable acidity 0.52 to 0.83 per cent, ascorbic acid 46 to 74.80 mg/100g and pH 3.92 to 4.98. The juice percent was determined in Kinnow 53.20 g after that Nagpur santra 51.30 g. The chemical attributes of Sweet Mandarin were found as total soluble solid varied from 8.96 to 12.20 per cent, reducing sugar 3.22 to 6.60 per cent, total sugar 5.73 to 10.04 per cent, titrable acidity 0.84 to 2.24 per cent, ascorbic acid 25.96 to 36.13mg/100 g and pH 3.84 to 4.60. However, the Sweet Orange cultivars Mosambi Local-3 and Mosambi Local-4 and Sweet Mandarin cv. Local Mandarin-1 were suitable for export, making of non alcoholic beverages, easy for bottling and frozen products grown under Lucknow conditions

    In vitro free radical scavenging activity of different extracts of Adansonia digitata L.

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    The species Adanasonia digitata L. (Bombacaceae) is a multipurpose tree with enormous range of medicinal and economic importance. The objective of the current study was to investigate the free radical scavenging potential of A. digitata. The methanol extracts of different parts i.e., leaf, seed, bark, fruit wall and floral extracts of A. digitata were screened for antioxidant activity using DPPH assay. Results from this study showed that the maximum and minimum percentage of free radical scavenging activity was exhibited by methanol extracts of seed and fruit wall (27.69 & 20) as measured by using DPPH assay. These results showed the antioxidant potential of this medicinal plant to make use in the preparation of drugs with free radical scavenging activity

    Indole Compounds and Their Use as Radiation Sensitizing Agents and Chemotherapeutic Agents

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    Indole derivatives that are useful in the treatment of cancer as a chemotherapeutic agent or radiosensitizing agent

    Near-Infrared Spectroscopy of Carbon-Enhanced Metal-Poor Stars. I. A SOAR/OSIRIS Pilot Study

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    We report on an abundance analysis for a pilot study of seven Carbon-Enhanced Metal-Poor (CEMP) stars, based on medium-resolution optical and near-infrared spectroscopy. The optical spectra are used to estimate [Fe/H], [C/Fe], [N/Fe], and [Ba/Fe] for our program stars. The near-infrared spectra, obtained during a limited early science run with the new SOAR 4.1m telescope and the Ohio State Infrared Imager and Spectrograph (OSIRIS), are used to obtain estimates of [O/Fe] and 12C/13C. The chemical abundances of CEMP stars are of importance for understanding the origin of CNO in the early Galaxy, as well as for placing constraints on the operation of the astrophysical s-process in very low-metallicity Asymptotic Giant Branch (AGB) stars. This pilot study includes a few stars with previously measured [Fe/H], [C/Fe], [N/Fe],[O/Fe], 12C/13C, and [Ba/Fe], based on high-resolution optical spectra obtained with large-aperture telescopes. Our analysis demonstrates that we are able to achieve reasonably accurate determinations of these quantities for CEMP stars from moderate-resolution optical and near-infrared spectra. This opens the pathway for the study of significantly larger samples of CEMP stars in the near future. Furthermore, the ability to measure [Ba/Fe] for (at least the cooler) CEMP stars should enable one to separate stars that are likely to be associated with s-process enhancements (the CEMP-s stars) from those that do not exhibit neutron-capture enhancements (the CEMP-no stars).Comment: 27 pages, including 5 tables, 6 figures, accepted for publication in The Astronomical Journa

    Automated Determination of [Fe/H] and [C/Fe] from Low-Resolution Spectroscopy

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    We develop an automated spectral synthesis technique for the estimation of metallicities ([Fe/H]) and carbon abundances ([C/Fe]) for metal-poor stars, including carbon-enhanced metal-poor stars, for which other methods may prove insufficient. This technique, autoMOOG, is designed to operate on relatively strong features visible in even low- to medium-resolution spectra, yielding results comparable to much more telescope-intensive high-resolution studies. We validate this method by comparison with 913 stars which have existing high-resolution and low- to medium-resolution to medium-resolution spectra, and that cover a wide range of stellar parameters. We find that at low metallicities ([Fe/H] < -2.0), we successfully recover both the metallicity and carbon abundance, where possible, with an accuracy of ~ 0.20 dex. At higher metallicities, due to issues of continuum placement in spectral normalization done prior to the running of autoMOOG, a general underestimate of the overall metallicity of a star is seen, although the carbon abundance is still successfully recovered. As a result, this method is only recommended for use on samples of stars of known sufficiently low metallicity. For these low-metallicity stars, however, autoMOOG performs much more consistently and quickly than similar, existing techniques, which should allow for analyses of large samples of metal-poor stars in the near future. Steps to improve and correct the continuum placement difficulties are being pursued.Comment: 8 pages, 7 figures; accepted for publication in A

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    Optimización de un pretratamiento enzimático para semillas de mostaza utilizando metodología de superficie de respuesta

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    In order to investigate the effect of an enzymatic pre-treatment process for the extraction of oil from black mustard seeds (Brassica nigra) using viscozyme, the reaction parameters such as temperature, buffer-to-seed ratio and enzyme concentration were considered as determinant factors in the central composite design. Optimization was carried out according to the four-variable five-level central composite design of experiments. The effects of enzyme concentration (5–12%), temperature (40–55 °C), pH (5.0–6.0), and reaction time (1–7 h) on the free oil liberated were studied. Residual oil was collected by subjecting the treated meal to soxhlet extraction for 4 h. An enzyme dose of 7.5% (w/w), pH 5.0, 50 °C, and 5 h with constant shaking at 450 rpm were found to be opti­mal conditions. Centrifuging the mixture at 7000 rpm for 30 min separated the oil with a recovery of 71–73.1%.Con el fin de investigar el efecto de un pretratamiento enzimático para la extracción de aceite de semillas de mostaza negra (Brassica nigra) utilizando viscozima, los parámetros de la reacción, como la temperatura, la relación de tampón/semilla y las concentraciones de enzima, se consideraron factores deter­minantes en el diseño. La optimización se llevó a cabo mediante cuatro diseños de experimentos compuestos de cinco niveles. Se estudió el efecto de la concentración de enzima (5-12%), temperatura (40-55 °C), pH (5.0-6.0), y tiempo de reacción (1-7 h) sobre el aceite liberado. El aceite residual se recolectó sometiendo la pasta tratada a una extracción de soxhlet durante 4 h. Las dosis de enzima del 7,5% (p/p), pH 5,0, 50 °C y 5 h con agitación constante a 450 rpm fueron las condiciones óptimas. La centrifugación de la mezcla a 7000 rpm durante 30 minutos separó el aceite con una recuperación de 71-73.1%

    Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from the SDSS/SEGUE Sample

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    The chemical compositions of seven Carbon-Enhanced Metal-Poor (CEMP) turn-off stars are determined from high-resolution spectroscopy. Five of them are selected from the SDSS/SEGUE sample of metal-poor stars. The effective temperatures of these objects are all higher than 6000 K, while their metallicities, parametrized by [Fe/H], are all below -2. Six of our program objects exhibit high abundance ratios of barium ([Ba/H]> +1), suggesting large contributions of the products of former AGB companions via mass transfer across binary systems. Combining our results with previous studies provides a total of 20 CEMP main-sequence turn-off stars for which the abundances of carbon and at least some neutron-capture elements are determined. Inspection of the [C/H] ratios for this sample of CEMP turn-off stars show that they are generally higher than those of CEMP giants; their dispersion in this ratio is also smaller. We take these results to indicate that the carbon-enhanced material provided from the companion AGB star is preserved at the surface of turn-off stars with no significant dilution. In contrast, a large dispersion in the observed [Ba/H] is found for the sample of CEMP turn-off stars, suggesting that the efficiency of the s-process in very metal-poor AGB stars may differ greatly from star to star. Four of the six stars from the SDSS/SEGUE sample exhibit kinematics that are associated with membership in the outer-halo population, a remarkably high fraction.Comment: 45 pages, 10 figures, 10 tables, Astrophysical Journal, in pres
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