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Late Holocene morphodynamic evolution of Thamirabarani delta and Thoothukudi tombolo in South India: insights from integrated analysis of early cartographic documents and satellite images
No full textThe age of discovery and exploration (fifteenth-sixteenth century CE) in Europe and later colonisation of newly explored territories by Portuguese, Spanish, Danish, French, Dutch, and British led to extensive mapping/charting of coastal regions around the globe for navigation, as well as for political and military purposes. These sea charts and coastal maps contain rich geomorphological details and offer unique geographical inputs for studying past geomorphic processes. By meticulously combining data from early sea charts, maps, historical textual records, and satellite images, the current study intends to illustrate their relevance in comprehending the long-term (from the past few centuries to a few thousand years) geomorphological processes. The study area includes the coast of the Thamirabarani delta and the Thoothukudi coast in southeast Tamil Nadu, which is known for its historically important ports, viz. Korkai and Kayal or Palayakayal. These places, were functional ports in the past, are now located a few kilometres inland. This study provides the following multifaceted outcomes: 1) offered a novel understanding of the morphodynamic evolution of the Thamirabarani delta and Thoothukudi tombolo; 2) revealed the value of early maps not only in tracing the geomorphic dynamics and dating the observed changes but also in developing a better understanding of the interpretation keys of remote sensing data; 3) provided an understanding of anthropogenic impressions on the landscape (street pattern or agricultural field pattern) driven by geomorphic changes; the identification of these patterns help validating the content of early maps. Integrated study of early cartographic documents (widely available in various archives and libraries around the world) has a high potential to advance the understanding of the morphodynamic evolution of various coastal landforms at a global scale
Annular vertical cylindrical thermochemical storage system with innovative flow arrangements for improved heat dispatch towards space heating requirements
No full textThermochemical energy storage is a potential solution for low-temperature seasonal energy storage systems and for improving renewable solar thermal energy share in the global energy mix. Such systems can help in meeting the heating requirements in the Indian Himalayan region in an environment-friendly manner. A few studies have attempted to understand the performance of strontium bromide hexahydrate-monohydrate-based storage as a thermochemical energy storage medium. The present study evaluates the performance of the vertical cylindrical annular reactor configuration, considering innovative radial airflow configurations. A two-dimensional axisymmetric model has been developed to study the effect of the various geometrical and operating parameters. During the charging (dehydration) process, the outward flow configuration exhibits substantially higher exergy efficiency as against the inward flow counterpart, with the difference being more pronounced (∼6–8%) at lower aspect ratios (0.5–1.0). The flow work requirement is higher for the outward flow during the hydration (discharging process), resulting in better performance for the inward flow counterpart. Upon increasing the volumetric air flow rate, the pressure drop across the reactive bed is found to increase substantially, leading to lower exergy efficiencies for higher flow rates. During the hydration process, the exergy efficiency for the inward flow becomes almost constant (∼15%) for a relative humidity level exceeding 60%, whereas that for the outward flow gradually increases to reach ∼ 5% for an 80% relative humidity. The ratio of thermal energy stored to the flow work required is higher for the outward flow. The energy output to flow work ratio is about 35% higher for the inward flow for the aspect ratio of 4
The Cost of Climate Change Heightened Sexual and Gender-Based Violence: A Challenge for International Law
No full textMyriad Ways in Which Things Could Have Gone Wrong but Did Not
No full textThe Variable Energy Cyclotron Center (VECC) at Kolkata has a K130 room-temperature cyclotron that has been operating since 1977, a K500 Cyclotron operating since 2009, a K30 medical cyclotron and a radioactive ion beam facililty. It has a large number of very high voltage or very high current power supplies, liquid helium plants, and very many vacuum pumps sophisticated and delicate equipment. Yet, in the last more than 5 decades of its operation there have been no serious accidents or leakage of radioactivity. This has been possible by a strict regime of retraining and strict adherence to standard security precaution, and an active and understanding leadership. This chapter describes some of these efforts
Geospatial modelling for estimation of PM2.5 concentrations in Major cities of Peninsular India (NIAS/NSE/EECP/U/RR/03/23)
Get PDFFine particulate matter (PM2.5) pollution is a primary global public
health concern. Exposure to PM2.5 pollution beyond the safe limits
of exposure is associated inter alia with respiratory and cardiovascular mortality and morbidity. However, the baseline and
background levels of PM2.5 concentration in megacities in India are
significantly higher than the WHO Air Quality Guidelines which
are based on studies conducted in regions with very low ambient
PM concentrations. Human susceptibility to air pollution may vary
based on age distribution, nutritional intake, access to health care,
meteorological conditions, and any natural immunity. Therefore, it
is essential to study the exposure-response function(s) specific to
India using the local air pollution exposure studies.
On the other hand, the air quality monitoring stations used to
measure ambient PM2.5 concentration are sparse and non-uniformly
distributed in urban areas and nearly-absent in rural areas leading to
the misclassification of exposure in India.
Therefore, the authors have developed a Linear Mixed Effects
model in the present study to estimate PM2.5 levels in four major
cities in peninsular India at a spatial resolution of 1 km x 1 km.
Bengaluru (801 grids), Hyderabad (873 grids), Madurai (81 grids),
and Vijayawada (88 grids) have been selected for this study since
they are useful to estimate air pollution exposures for cities with
different geographical, climatical, demographic and topographical
conditions
Neurochaos feature transformation for Machine Learning
No full textWith today’s increasing data complexity, efficient feature extraction has become an integral part of learning. In this spirit, we use features from a recently proposed brain-inspired learning algorithm for classification namely Neurochaos Learning (NL). This paper compares NL: chaos-based hybrid ML architectures to stand-alone ML/NL architectures. The maximum performance boost obtained is 25.97% (Statlog (Heart) dataset using NL features+Decision Tree) in the high training sample regime and 144.38% (Haberman’s Survival dataset using NL features+Random Forest) in the low training sample regime. NL offers enormous flexibility in integrating Neurochaos features with any ML classifier
Russian trenches major challenge for Ukraine's counter-offensive
No full textDespite technological advances, trenches remain an important part of defensive strategy
Model simulation of carbonaceous fine particulate matter using SAFAR emission inventory and comparison with EDGAR-HTAP simulations
No full textIn this study, the evaluation of carbonaceous fine particulate matter (C-PM) was conducted using the SAFAR-India regional model. Two emission inventories were utilized: the newly developed SAFAR inventory and the global EDGAR-HTAP inventory, both for the year 2018. The simulation aimed to capture the seasonal and spatial patterns of black carbon (BC) and organic carbon (OC) concentrations. To validate model results, surface meteorological parameters, and C-PM concentrations were compared with the MERRA reanalysis data for the Indian region. Model simulated surface C-PM concentration with SAFAR emission inventory is found to be slightly overestimated (1.10), whereas simulated results with EDGAR emission inventory is significantly underestimated as compared to MERRA data. Model-simulated meteorological parameters showed a better correlation with MERRA reanalysis. Simulated geographical patterns of seasonal mean C-PM with SAFAR emission inventory exhibit quite a better comparison with MERRA reanalysis as against EDGAR simulated results. However, some differences in the present results are visible, particularly over the IGP region, as compared to MERRA data, but they are mainly attributed to a significant difference in the special resolution of present results (much finer) as compared to coarser MERRA data. In the Indo-Gangetic Plain (IGP) region, the concentration of BCSF and OCSF (BC and OC with SAFAR emission, respectively) show the peak during the winter, followed by the post-monsoon season. Although the correlation coefficients of hourly time series of surface BCSF and OCSF concentrations with MERRA over India are high (0.92 and 0.88), the poor RMSE, is attributed mainly to different scales of resolution. The model simulated BC, and OC concentrations with SAFAR emission input capture the pattern of spatial distribution reasonably well. The present evolution of BC and OC will help to better quantify their impact on climate and atmospheric conditions over the Indian region
Experimental Investigation of Stratified Sensible Thermal Energy Storage Using Silicone Oil
Get PDFThis study experimentally investigates the scarcely studied stratified, oil-based sensible thermal energy storage (STES) tank, to examine the heat retention capability of Hytherm-600 silicone oil during the standalone period and its heat dispatchability during the discharging process. To conduct an experimental study on the thermic oil, a vertical cylindrical tank with a helical discharging coil fitted inside is used. Three different oil charging temperatures (50, 70, and 90 °C), and three different discharging flow rates (water) through the helical coil (0.5, 1.25, and 2 L/min) have been considered. The thermal stratification phenomena in oil and the evolution of thermocline have been investigated. Results indicate the formation of a thermocline zone of 154 mm thickness in the lower portion of the tank within 3 h from the commencement of the stand-alone period. The discharging operation fluctuates the thermocline stability in the storage medium (i.e., commercial thermic oil Hytherm-600). During the discharging operation, a water flow rate of 0.5 L/min through the helical coil led to higher discharging efficiencies owing to better heat transfer attributable to the higher water residence time inside the coil. For the aforesaid water flow rate, the average discharging efficiencies are 85.6%, 75.6%, and 81.6% for the charging temperatures of 50, 70, and 90 °C, respectively. Finally, the primary thermocline thickness is found to be constant at 82 mm following the splitting of the initial thermocline during the discharging operation
