| 11. |
- Borwankar, Chinmay, et al.
(author)
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Simulation studies of MACE-I : Trigger rates and energy thresholds
- 2016
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In: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 84, s. 97-106
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Journal article (peer-reviewed)abstract
- The MACE (Major Atmospheric Cherenkov Experiment) is an upcoming Very High Energy (VHE) gamma-ray telescope, based on imaging atmospheric Cherenkov technique, being installed at Hanle, a high altitude astronomical site in Ladakh, India. Here we present Monte Carlo simulation studies of trigger rates and threshold energies of MACE in the zenith angle range of 0 degrees-60 degrees for on-axis gamma-ray coming from point source and various cosmic ray species. We have simulated the telescope's response to gamma-rays, proton, electron and alpha initiated atmospheric Extensive Air Showers (EAS) in the broad energy range of 5 GeV to 20 TeV. For gamma-rays we consider power law and log parabolic spectra while other particles are simulated with their respective cosmic ray spectrum. Trigger rates and threshold energies are estimated for the trigger configuration of 4 Close Cluster Nearest Neighbour(CCNN) pixels as implemented in MACE hardware, in combination with single channel discriminator threshold ranging from 6-10 photo electrons (pe). We find that MACE can achieve the gamma-ray trigger energy threshold of similar to 17 GeV (4 CCNN, 9 pe) at 0 degrees zenith angle for power law spectrum. The total trigger rate at 0 degrees zenith is expected to be similar to 650 Hz, with protons contributing similar to 80% to it. For the zenith range of 0 degrees-40 degrees we find that the telescope can achieve gamma-gray trigger threshold energies of similar to 22 GeV at 20 degrees zenith angle and similar to 40 GeV at 40 degrees zenith angle. Integral rates are also almost constant for this zenith angle range. At zenith angle of 60 degrees, trigger energy threshold increases to similar to 173 GeV and total integral rate falls down to similar to 305 Hz. (C) 2016 Elsevier B.V. All rights reserved.
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| 16. |
- Das, Oisik, et al.
(author)
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An Attempt to Find a Suitable Biomass for Biochar-Based Polypropylene Biocomposites
- 2018
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In: Environmental Management. - : Springer. - 0364-152X .- 1432-1009. ; 62:2, s. 403-413
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Journal article (peer-reviewed)abstract
- Four biomass wastes (rice husk, coffee husk, coarse wool, and landfill wood) were added with biochar and polypropylene (PP) to manufacture biocomposites. Individual biomasses were tested for their combustion behavior using cone calorimeter. Biocomposites were analyzed for their fire/thermal, mechanical, and morphological properties. Wood had the most desirable comprehensive effect on both the mechanical and fire properties of composites. In particular, wood and biochar composite exhibited the highest values of tensile/flexural properties with a relatively low peak heat release rate. In general, application of waste derived biochar and biomasses drastically reduced the susceptibility of neat PP towards fire.
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| 17. |
- Das, Oisik, et al.
(author)
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Biochar to the rescue : Balancing the fire performance and mechanical properties of polypropylene composites
- 2017
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In: Polymer degradation and stability. - : ELSEVIER SCI LTD. - 0141-3910 .- 1873-2321. ; 144, s. 485-496
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Journal article (peer-reviewed)abstract
- Biochar based wood/polypropylene (PP) composites were manufactured with two flame retardants (FRs): ammonium polyphosphate/APP and magnesium hydroxide/Mg(OH)(2). The amounts of wood and biochar were alternated for accommodating the FRs in each blend. Flammability and mechanical characterisation for both the batches containing different FRs were done. Having higher proportion of biochar and less wood is beneficial to reduce flammability. The thermally stable biochar contributes to formation of effective char to restrict O-2 transfer into PP. The higher weight ratio of biochar than wood in the composites compromised the tensile and flexural strengths to some extent as the APP and Mg(OH)(2) particles were trapped inside biochar pores consequently reducing the effectiveness of biochar pore infiltration by PP. In general, addition of biochar with a woody biomass (with FRs) to neat PP significantly impedes its flammability while enhancing certain mechanical properties, such as flexural strength and tensile/flexural moduli and preserving the tensile strength. (C) 2017 Elsevier Ltd. All rights reserved.
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| 18. |
- Das, Oisik, et al.
(author)
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The flammability of biocomposites
- 2018
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In: Durability and Life Prediction in Biocomposites, Fibre-Reinforced Composites and Hybrid Composites. - : Elsevier BV. ; , s. 335-365
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Book chapter (other academic/artistic)abstract
- Keeping sustainability in mind, polymer composites are usually fabricated with biobased materials instead of synthetics. However, these “biocomposites” often lack the required strength and are extremely susceptible to fire. This necessitates the application of fire-retardant treatment, which could render the composite fire resistant. This chapter gives an overview of the types of fire retardants that are generally applied, and a review of studies done to impart fire retardancy in composites. Several instruments and standards used for determining fire behaviors of composites are also described in detail. Biochar (especially made at high pyrolysis temperatures) is very resistant to ignition and thermally stable, owing to its extensive network of cross-linking between adjacent aromatic carbon sheets. Its inclusion in polymeric composites is advantageous for both fire and mechanical properties. The inherent fire-resistant and char-forming ability of wool (a natural protein fiber) has been exploited to develop composites that exhibit the highest degree of flame resistance (V0 rating in UL94 tests). Finally, wheat gluten, a by-product of the cereal industry, has shown potential regarding fire retardancy and thermal stability. Gluten's flame-resistant properties can be made even more potent by applying other additives (e.g., silica).
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| 19. |
- Mateescu, B., et al.
(author)
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Obstacles and opportunities in the functional analysis of extracellular vesicle RNA - An ISEV position paper
- 2017
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In: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 6:1
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Journal article (peer-reviewed)abstract
- The release of RNA-containing extracellular vesicles (EV) into the extracellular milieu has been demonstrated in a multitude of different in vitro cell systems and in a variety of body fluids. RNA-containing EV are in the limelight for their capacity to communicate genetically encoded messages to other cells, their suitability as candidate biomarkers for diseases, and their use as therapeutic agents. Although EV-RNA has attracted enormous interest from basic researchers, clinicians, and industry, we currently have limited knowledge on which mechanisms drive and regulate RNA incorporation into EV and on how RNAencoded messages affect signalling processes in EV-targeted cells. Moreover, EV-RNA research faces various technical challenges, such as standardisation of EV isolationmethods, optimisation of methodologies to isolate and characteriseminute quantities of RNA found in EV, and development of approaches to demonstrate functional transfer of EV-RNA in vivo. These topics were discussed at the 2015 EV-RNA workshop of the International Society for Extracellular Vesicles. This position paper was written by the participants of the workshop not only to give an overview of the current state of knowledge in the field, but also to clarify that our incomplete knowledge - of the nature of EV(-RNA)s and of how to effectively and reliably study them - currently prohibits the implementation of gold standards in EV-RNA research. In addition, this paper creates awareness of possibilities and limitations of currently used strategies to investigate EV-RNA and calls for caution in interpretation of the obtained data. © 2017 The Author(s).
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| 20. |
- Shekhar, Mayank, et al.
(author)
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Himalayan glaciers experienced significant mass loss during later phases of little ice age
- 2017
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Journal article (peer-reviewed)abstract
- To date, there is a gap in the data about the state and mass balance of glaciers in the climate-sensitive subtropical regions during the Little Ice Age (LIA). Here, based on an unprecedented tree-ring sampling coverage, we present the longest reconstructed mass balance record for the Western Himalayan glaciers, dating to 1615. Our results confirm that the later phase of LIA was substantially briefer and weaker in the Himalaya than in the Arctic and subarctic regions. Furthermore, analysis of the time-series of the mass-balance against other time-series shows clear evidence of the existence of (i) a significant glacial decay and a significantly weaker magnitude of glaciation during the latter half of the LIA; (ii) a weak regional mass balance dependence on either the El Niño-Southern Oscillation (ENSO) or the Total Solar Irradiance (TSI) taken in isolation, but a considerable combined influence of both of them during the LIA; and (iii) in addition to anthropogenic climate change, the strong effect from the increased yearly concurrence of extremely high TSI with El Niño over the past five decades, resulting in severe glacial mass loss. The generated mass balance time-series can serve as a source of reliable reconstructed data to the scientific community.
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