2835 research outputs found
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Black Carbon Characteristics over a Semi-urban Environment in the Garhwal Himalayas
No full textBlack carbon (BC) concentrations were measured over a semi-urban location in Srinagar (Garhwal) in the central Himalaya from October 2019 to September 2020. The BC ranged between 0.7 and 3.4 µg m−3 in different months. The highest BC concentration was observed in the post-monsoon season. The long-range transport and biomass burning (BB) were found to be the major reason for BC over the region. The k values over the region ranged between − 0.004 and 0.004 in different months and indicate that aged BC was present during monsoon periods because of long-range transport. However, fresh BC was present during November, December and February (relatively fresh BC in other months). The BB contribution was up to 58%. Brown carbon (BrC) showed a similar seasonal pattern as black carbon. The BC values in the COVID-19 lockdown period were analyzed and were low compared to very high values in the same season a year before. The influence of long-range transport and forest fire incidents on BC mass concentrations is illustrated in detail. Hence, this study provides an insight into the amount of BC production due to human activity. The BC of anthropogenic origin over this region should be controlled because of its proximity to adjacent glaciers to avoid excessive BC transport to these vulnerable regions
Development of a high-resolution emissions inventory of carbonaceous particulate matters and their growth during 2011–2018 over India
No full textThe carbonaceous fine particulate matters (BC and OC) are of significant concern for air quality and climate change. A high-resolution (10 × 10 km2) gridded SAFAR (System of Air Quality and Weather Forecasting And Research) emission inventory of BC-OC has been developed for 2011 and 2018 over India using bottom-up Geographical Information Systems (GIS) based statistical model with the latest activity data and updated emission factors. The emission inventory accounted for major sectors like transport, residential, industries, Thermal Power Plant (TPP), and rest (Mobile towers, Irrigation pumps, Municipal solid waste burning, Waste to energy plants, Construction, Crematorium, Incense stick, Brick kiln). The total national BC and OC emissions for the latest year, 2018 are estimated to be 1480 Gg yr−1 and 3116 Gg yr−1, respectively. The most dominant sector is found to be the transportation sector for BC with 46% share, whereas the residential sector for OC with 39% share. An overall growth of 32% and 36% is estimated in 2018 compared to 2011 for BC and OC, respectively. The highest growth during the past 8 years is found in the transport sector whereas the residential sector has recorded the lowest growth rate. The latter is mainly due to a decline in kerosene oil, and domestic wood after the government introduced the ambitious Ujjwala scheme to replace bio-fuel with LPG. This high-resolution inventory of BC-OC will be helpful to policymakers in identifying the hotspot regions and prioritizing mitigation options, thus benefitting Human health and climate. The current gridded emissions will provide much-needed input for the regional chemistry transport models
The ocean carbon sinks and climate change
No full textThe oceans act as major carbon dioxide sinks, greatly influencing global climate. Knowing how these sinks evolve would advance our understanding of climate dynamics. We construct a conceptual box model for the oceans to predict the temporal and spatial evolution of CO2
of each ocean, and the time-evolution of their salinities. Surface currents, deep water flows, freshwater influx, and major fluvial contributions are considered, as also the effect of changing temperature with time. We uncover the strongest carbon uptake to be from the Southern Ocean, followed by the Atlantic. The North Atlantic evolves into the most saline ocean with time and increasing temperatures. The Amazon River is found to have significant effects on CO2
sequestration trends. An alternative flow scenario of the Amazon is investigated, giving interesting insights into the global climate in the Miocene epoch
Study of Different Flow Configurations of Radial Flow Annular Reactor for Thermochemical Energy Storage
Get PDFThermochemical energy storage is emerging as a promising seasonal thermal energy storage technology. Strontium Bromide has recently become one of the most used salt hydrates for the salt-hydrate and moist airbased open thermochemical energy storage system. This article suggests that radial flow fixed bed reactors offer advantageous configurations owing to their lower pressure drop without compromising thermal performance. Four possible configurations of radial flow fixed bed reactors, Inward flow Π-type, Inward flow Z-type, Outward flow Π-type, and Outward flow Z-type, are analyzed in detail. Energy efficiency, exergy efficiency, pressure drop, and non-dimensional constant named non-uniformity are used as performance metrics for comparing the proposed configurations with four different combinations of flow rates and aspect ratios. It is found that the type of the reactor configuration (Π-type or Z-type) has a negligible impact on the performance, with a maximum change of 4% in the energy efficiency during the hydration phase. The inward and outward flow arrangements exhibit considerable differences in performance, with inward flow having 3.5 times higher exergy efficiency than outward flow. The π-type configuration shows the highest non-uniformity of -0.22 for an aspect ratio of four, with a flow rate of 50 m3/h
35th Senior Executives Programme on "Leadership in a World of Uncertainties" 16-21 January 2023
No full textThe animal tracking’s agency: Why are camera traps and GPS collars new research agents in the interaction between humans and other animals ?
No full textThere has been, of late, growing interest across the social and natural sciences in the potential of image-based methodologies to investigate embodied and affective more-than-human, multispecies lifeworlds beyond more traditional research methods that remain confined to mere human representations. Such methodologies could potentially contribute to the etho-ethnographic approaches that allow us to examine the lived experiences and cognitive responses of nonhuman organisms to human–nonhuman entanglements across locations, practices, encounters and traditional cultures. In what follows we will draw from different experimental projects and case studies to reflect on how and why the use of camera traps or other technologies like GPS collars transform research and research conduct. Similarly we will outline how animals themselves ‘see’ and adapt to modern technologies and the ethical implications of it
‘Why Can’t Our Bhuta Have a Mask?’ Caste Contestations and Ritual Practice in Tulunadu
No full textThe paper describes caste contestations around the Bhutaradhane tradition in the Tulunadu region of coastal Karnataka. Bhutaradhane is a pantheistic tradition of spirit worship which has been a key site for the assertion of regional identity claims in Tulunadu. The Bhutas (spirits) are ranked along a graded hierarchy that reflects the caste structure of the region. Drawing on ethnographic fieldwork, the paper describes the interventions of a Dalit caste, the Mundalas, to rupture this hierarchical structure and challenge their low assigned status in the tradition and in society. It explores how they draw on narratives of the past to appropriate and reshape the Bhutaradhane tradition in line with their aspirations for upward mobility. The paper situates current contestations around the caste’s patron Bhuta within the growing socio-political consciousness of the Mundalas, who have challenged the hegemonic discourse of Bhuta heritage, laying bare the operations of caste within the ritual as well as caste inequalities and exclusions in the region