45 research outputs found

    Supernova SN 2012dn: A spectroscopic clone of SN 2006gz

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    We present optical and UV analysis of the luminous type Ia supernova SN 2012dn covering the period \sim -11 to +109 days with respect to the BB band maximum, that occurred on JD 2456132.89 ±\pm 0.19, with an apparent magnitude of mBmaxm_{B}^\text{max} = 14.38 ±\pm 0.02. The absolute magnitudes at maximum in BB and VV bands are MBmax=19.52±0.15M_{B}^\text{max} = -19.52 \pm 0.15 and MVmax=19.42±0.15M_{V}^\text{max} = -19.42 \pm 0.15, respectively. SN 2012dn is marginally luminous compared to normal type Ia supernovae. The peak bolometric luminosity of logLbolmax=43.27±0.06\log L_\text{bol}^\text{max} = 43.27 \pm 0.06 erg s1^{-1} suggests that 0.82±0.120.82 \pm 0.12 M_\odot of 56^{56}Ni was synthesized in the explosion. The decline rate Δm15(B)true=0.92±0.04\Delta m_{15}(B)_\text{true}= 0.92 \pm 0.04 mag is lower than that of normal type Ia supernovae, and similar to the luminous SN 1991T. However, the photometric and spectroscopic behaviour of SN 2012dn is different from that of SN 1991T. Early phase light curves in RR and II bands are very broad. The II band peak has a plateau-like appearance similar to the super-Chandra SN 2009dc. Pre-maximum spectra show clear evidence of C\,{\sc ii} 6580 \AA\, line, indicating the presence of unburned materials. The velocity evolution of C\,{\ sc ii} line is peculiar. Except for the very early phase (\sim-13 d), the C\,{\sc ii} line velocity is lower than the velocity estimated using the Si\,{\sc ii} line. During the pre-maximum and close to maximum phase, to reproduce observed shape of the spectra, the synthetic spectrum code {\sc syn++} needs significantly higher blackbody temperature than those required for normal type Ia events. The photospheric velocity evolution and other spectral properties are similar to those of the carbon-rich SN 2006gz.Comment: Accepted for publication in MNRAS, 19 pages, 20 figure

    A Hybrid Microgrid Operated by PV Wind and Diesel Generator with Advanced Control Strategy

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    All for a local area that gets its power from a solitary diesel generator (DG), this examination presents an efficient power energy choice for a microgrid. A twin feed enlistment generator draws power from a sun oriented photovoltaic (PV) cluster and the breeze to run this microgrid's electrical gear (DFIG). Two voltage source converters (VSCs) are sequentially coupled on the rotor side of the DFIG and share a DC transport that at last prompts the photovoltaic modules. Likewise associated with a similar DC transport as the DFIG stator is a bidirectional buck/help DC converter and a battery energy capacity (BES) to retain any overflow power. Most extreme energy collecting from the breeze and sun is accomplished by regulation of the bidirectional buck/help DC converter and the rotor side VSC. A changed form of the irritate and notice (P&O) technique is introduced for of expanding the energy result of a PV framework. Endeavors are being made to change VSC on the heap side to further develop DG's eco-friendliness. The ideal fuel-use reference DG power result may now be resolved utilizing a new, more broad methodology. Using the Sim Power Systems toolbox in MATLAB, we model and simulate many scenarios, including fluctuating wind speeds, fluctuating insolation, the impact of fluctuating load conditions on a bidirectional converter, and an unbalanced nonlinear load linked at the point of common coupling (PCC). Finding sinusoidal and balanced DG and DFIG stator currents

    Chemical composition of Abrus precatorius L. seeds

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    Aims: A. precatorius seed powder is traditionally used in Ayurveda, Siddha and Unani medicine. The objective of present work is to describe the oil, starch, protein, polyphenol and mineral composition of A. precatorius seeds. Methodology: Legumes from A. precatorius were collected, and seeds were manually separated. Dried seeds in powder form were employed for the various analyses: solvent extraction was used for elucidation of the oil percentage value; starch content was determined by the enzymatic method; total polyphenol and flavonoid contents were spectrophotometrically analyzed using Folin-Ciocalteu and aluminum chloride as the color developing reagents, respectively; and X-ray fluorescence (XRF) was used for the mineral contents assessment. Results: The seed kernel consisted of stored oil (3.2%), protein (92.0%) and starch (4.8%). The total polyphenol and flavonoid contents were 24710 and 2520 mg/kg (dw). A remarkably high content of polyphenols was observed in the seed coat and the seed pod. P, S and (mainly) K nutrients were hyper-accumulated in the seed kernel. The seeds showed a glass transition at -21°C, two endothermic peaks at 109°C (dehydration and protein unfolding) and at 209°C, and a calorific value (~406 kcal/100 g dw) that exceeded those of Pisum sativum L., Lens culinaris Medik. and other common pulses. Conclusions: The seed kernel from A. precatorius was mainly composed of stored protein, with low oil and starch contents. High contents of polyphenols, K, Mg, Ca and Fe were found in the seeds. Heavy metals were below the safety limits established for human consumption

    Chemical composition of Caesalpinioideae seeds

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    Aims: Caesalpinioideae species have great medicinal and food values. In this work, six Caesalpinioideae species that grow abundantly in central India were selected for chemical investigation: Delonix regia, Entada gigas, Leucaena leucocephala, Mimosa pudica, Parkia javanica and Senna siamea. The objective of the present work is to describe the phytochemical and mineral composition and the bioaccumulation potentialities of the seeds from aforementioned species. Methodology: Spectrophotometric, enzymatic and X-ray fluorescence spectrophotometric techniques were used for the quantification of polyphenols, starch and mineral contents, respectively. Results: The sum of the total concentrations of 17 macro- and micronutrients (P, S, Cl, K, Rb, Mg, Ca, Sr, Cr, Mn, Fe, Co, Cu, Zn, Se, Mo and Pb), oil, protein and total starch in the six seeds were in the 20253-78489 mg/kg, 3.1-30.1%, 52.9-91.5% and 5.4–41.0% range, respectively. The highest concentrations of Fe, oil and phenolics were observed in M. pudica seeds. Both thermal and spectral characteristics allowed to differentiate M. pudica and P. javanica seeds (with the highest caloric contents) from the seeds from the other species. Conclusion: The selected Caesalpinioideae seeds are potential sources of the nutrients (i.e., P, S, K, Mg, Ca and Fe) and polyphenols, which are needed for biological metabolism and human health. The presence of heavy metals was well below safety limits, enabling their medicinal uses

    Nutritional, spectral and thermal characteristics of Lamiaceae seeds

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    Aims: Species of the family Lamiaceae possess a rich tradition of use for flavoring and medicinal purposes. This paper focusses on the nutritional and thermal characteristics of the seeds from eight species belonging to this family: Gmelina arborea Roxb. ex Sm., Hyptis suaveolens (L.) Poit., Leonotis nepetifolia (L.) R.Br., Ocimum americanum L., Ocimum sanctum L. (Rama Tulsi), Ocimum tenuiflorum L. (Krishna Tulsi), Origanum vulgare L. and Tectona grandis L.f. Methodology: The oil, starch, total polyphenol, flavonoid and mineral contents for aforementioned seeds were determined. Fourier-transform infrared (FTIR) spectroscopy was used to assess the phytoconstituents. Thermogravimetric/derivative thermogravimetric analyses (TG/DTG) and differential scanning calorimetry (DSC) analyses were performed to analyze the decomposition patterns. Results: The concentrations of oil, starch, total polyphenol, flavonoids and minerals for the seeds from the eight plants under study ranged from 11.8 to 50.4%, from 0.22 to 1.84%, from 295 to 5842 mg/kg, from 1660 to 12680 mg/kg and from 11756 to 33927 mg/kg, respectively. Unsaturated oils, polyphenols and lignin were recognized by vibrational spectroscopy. The sequence of thermal effects in the seed pyrolysis process above 100°C have been put in relation to seed protein crystallization (endotherm at 200°C), oxidation reactions and degradation of hemicellulose and other fiber components (at around 300°C), and decomposition of polyunsaturated (at 357°C) and mono-unsaturated (at 391°C) triglycerides. Conclusion: Lamiaceae seeds are potential food alternatives to cereals

    Type Ia supernovae SN 2013bz, PSN J0910+5003 and ASASSN-16ex: similar to 09dc-like?

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    We present optical photometric and spectroscopic studies of three supernovae (SNe) SN 2013bz, PSN J0910+5003 and ASASSN-16ex. UV-optical photometric data of ASASSN-16ex obtained with Swift-UVOT are also analyzed. These objects were initially classified as 09dc-like type Ia SNe. The decline rate parameters (Δm15(B)true\Delta m_{15}(B)_{true}) are derived as 0.92 ±\pm 0.04 (SN 2013bz), 0.70 ±\pm 0.05 (PSN J0910+5003) and 0.73 ±\pm 0.03 (ASASSN-16ex). The estimated BB band absolute magnitudes at maximum: -19.61 ±\pm 0.20 mag for SN 2013bz, -19.44 ±\pm 0.20 mag for PSN J0910+5003 and -19.78 ±\pm 0.20 mag for ASASSN-16ex indicate that all the three objects are relatively bright. The peak bolometric luminosities for these objects are derived as logLbolmax=\log L_\text{bol}^\text{max} = 43.38 ±\pm 0.07 erg s1^{-1}, 43.26 ±\pm 0.07 erg s1^{-1} and 43.40 ±\pm 0.06 erg s1^{-1}, respectively. The spectral and velocity evolution of SN 2013bz is similar to a normal SN Ia, hence it appears to be a luminous, normal type Ia supernova. On the other hand, the light curves of PSN J0910+5003 and ASASSN-16ex are broad and exhibit properties similar to 09dc-like SNe Ia. Their spectroscopic evolution shows similarity with 09dc-like SNe, strong CII lines are seen in the pre-maximum spectra of these two events. Their photospheric velocity evolution is similar to SN 2006gz. Further, in the UV bands, ASASSN-16ex is very blue like other 09dc-like SNe Ia.Comment: 19 pages, 20 figures, accepted for publication in MNRA
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