Title : Li-Be-B systematics in time-varying early forming solar system objects
Date : 09-09-2022
Time : 16:00:00
Speaker : Vikram Goyal
Area : Planetary Sciences Division
Venue : Seminar Room # 113/114 (Thaltej Campus)
Chondrites, the most primitive meteorites, preserve chronological information of the Solar System formation that took place ~4.56 Ga ago. Major constituents of chondrites include Calcium-Aluminium-rich Inclusions (CAIs) followed by AOAs and Chondrules. These have been dated to have formed within the first few million years of solar system formation and thus preserve a record of the earliest stages of the Solar System formation. Al-Rich Chondrules(ARCs) are special as they contain high abundance of corundum (>10%); corundum being a refractory mineral, it petrologically links two other major chondritic components, ferromagnesian chondrules (FMCs) and CAIs (supposedly, first forming solids). We know, short-lived radionuclides (SLN) are radioactive nuclei having a very short half-life compared to the age of the solar system. Study of origin of the few specific SLNs can impose a stringent constraint on the early solar activities. In this talk, I will discuss Li-Be-B systematics, an important system in the studies of short-lived radionuclides. Because of its very short half-life of just 53days, the measurement of 7Be confirms the presence of the irradiation process and also puts constraints on the early solar activity. Here, we discuss the importance of studying various early forming solids (in chronological order) to build Solar activity profile for first few million years.
Date : 07-09-2022
Time : 16:00:00
Speaker : Dr. Shailesh Nayak
Area : DEAN'S OFFICE
Venue : ONLINE
The ‘Blue Economy’ has been defined as an ocean-dependent economic development to improve quality of life of people while ensuring inclusive social development as well as environmental and ecological security. India has been committed to advance the “Blue Economy” and several programs have been initiated to promote blue economy in the country. The knowledge about seabed, marine mineral and energy resources, fishery resources, natural hazards in the Exclusive Economic Zone (EEZ), legal continental shelf (LCS) as well as High Seas is a pre-requisite for growth and development. The marine fish catch is about 3.7 million tons for last several years. The exploration of deep-water fishery indicated availability of about 3.3 million tons. Many new grounds of fishery between 200-2000 m have been identified. The technological challenges of harvesting, post-harvesting and processing for product development must be undertaken for commercialization of deep-sea fishery. Geophysical and bathymetric surveys of the EEZ, LCS and High Seas have provided information about placer minerals on the coast and nearshore waters, gas hydrates on continental shelf areas as well as manganese nodules, hydrothermal systems, and cobalt crusts in High Seas. The investment in developing technologies for harnessing these resources has been made as a part of ‘Deep Sea Mission.’ Similar investment needs to be made in developing human resources. The resultant increase in anthropogenic activities on the coast along with impacts of climate change will affect the environment and ecology of the coastal zone. The coast is also vulnerable to many hazards such as cyclones, storm surges, tsunamis, coastal erosion, sea level rise, etc. The managing coastal zone for ensuring ecological and livelihood securities along with advancing developmental activities is a challenge. The coastal and marine spatial mapping including coastal vulnerability should be used to understand risks involved, and accordingly, developmental activities should be planned. Regular satellite-based monitoring of coastal ecosystems is a vital requirement of such planning. There is now consensus that macro-economic decisions about the blue economy will need environmental data. The economic growth prospects in the ocean beyond 2030 will be limited without large investments to support ocean environments. We need to develop a framework to bring together disparate data sources by developing an accounting system for oceans. Lastly, we need to set up an institutional framework for implementing activities related to blue economy. We need invest in building infrastructure, human resources, finances, and governance system. Such investments in sustainable development of oceans will pay rich dividends for future generations for the benefit of humanity.