LIST OF COLLOQUIUM

Date : 04-08-2021
Time : 16:00:00
Speaker : Prof. Harold C. Connolly Jr
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

The OSIRIS-REx space mission is part of NASA's New Frontiers program and has a main goal of returning at least 60 g of pristine regolith from asteroid Bennu. On May 10th of this year, the spacecraft successfully performed a departure maneuver and left the vicinity of the Target asteroid, having achieved all of its science and engineering goals flawlessly, including the collection of regolith from asteroid Bennu. This talk will review the mission, the major findings of the mission as they pertain to sample science, discussion how our finding may illuminate the origins and evolution of the collected regolith. It will review the OSIRIS-REx collection and stowing (or the sample) process, what we know about the collected sample, and review some basic aspects of how the team will analyze and curate the sample when it returns.

Date : 24-03-2021
Time : 16:00:00
Speaker : Prof. Devesh K Sinha
Area : DEAN'S OFFICE
Venue : Online

Abstract

Ocean circulation plays a vital role in modulating the world’s climate. Surface currents moving from low to high latitudes deliver immense heat to the colder region and moderate the climate. One of the best examples is Gulf Stream which is considered to save North America and Europe from the extremely cold climate. The thermohaline circulation translates itself into the great ocean conveyor belt, which connects the world oceans through the surface and deep currents. The cold oceans are also a huge sink for the atmospheric carbon dioxide, while the warm oceans are the sources. The surface ocean circulation is largely controlled by the ocean-continent geometry, which has been changing through geological time. The changes have resulted in the opening and closing of major ocean gateways causing major climatic events, including the formation of the permanent ice cap on Antarctica, Northern Hemisphere Glaciation and East African aridification. During Cenozoic, the plate movements caused the opening of the Drake Passage and Tasman gateway, which resulted in the establishment of the Antarctic Circum Polar Current, a major cause for the development of ice sheets in Antarctica. The deepening of the Greenland-Scotland Ridge in the North Atlantic allowed the establishment of the North Component Deep Water and Atlantic Meridional Ocean Circulation (AMOC). The closing of the Indonesian Seaway resulted in East African aridification in the Early Pliocene, while during Late Pliocene, the closing of the Central American Seaway is attributed to enhance the northern hemisphere glaciation. Foraminiferal biogeographic and biostratigraphic studies have been very instrumental in understanding the opening and closing of the ocean gateways during the Cenozoic and their impact on palaeoceanography and paleoclimatic changes.

Date : 17-03-2021
Time : 16:00:00
Speaker : Prof. Tanusri Saha-Dasgupta
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

The electrical, magnetic, and optical properties of materials are controlled by their composition and structure. The structure, and also the strength of materials are determined by the chemical bonding between the atoms. At the root of all of these, the physical as well as the chemical properties, are the electrons. In this talk, we will demonstrate, how electronic structure calculations can be employed to modeling of complex materials and to gain insights to complicated physical and chemical processes happening in a complex material. Examples will be drawn from diverse areas e.g. high Tc cuprates, magneto-electric double perovskites, quantum spin compounds, metal-organics.

Date : 03-03-2021
Time : 16:00:00
Speaker : Prof. Bimla Buti
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

Plasma science provides one of the cornerstones of our knowledge of the Sun, the stars, the interstellar medium etc. Although it is often not readily apparent, plasma science is relevant to our society in a variety of ways. Plasma science is central to the development of nuclear fusion as a clean, renewable energy source. Coherent laser-plasma radiation sources have a variety of potential applications in medicine and industry. The role of Coherent, Chaotic and Turbulent processes in plasmas will be reviewed in this presentation. A brief description of Chaos and Fractals vis-à-vis Artificial Intelligence will also be presented.

Date : 03-02-2021
Time : 16:00:00
Speaker : Dr. Bhaskar Mukherjee
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

Outer space is continuously bombarded by energetic particles of galactic origin as well as protons of a wide energy distribution resulting from coronal mass ejection from the Sun designated as galactic cosmic rays (GCR), and solar particle events (SPE), respectively. Astronauts in space missions are directly exposed to GCR and SPE radiations. On the other hand, pilots and aircrew during long haul intercontinental flights and human population living in high-altitude mountainous regions are exposed to secondary radiations originated from cosmic ray shower (CRS) in the upper atmosphere. Using widely available Lithium Fluoride (LiF) and Beryllium Oxide (BeO) thermoluminescent dosimeter (TLD) chips a novel radiation dosimeter emulating “Mammalian Tissue-Equivalence” the LiBe-Micro Dosimeter was developed. The R&D pathway of LiBe-Micro-Dosimeter and important results including radiation dosimetry, risk assessment and radiation protection issues of astronauts resulting from space missions will be presented.

Date : 27-01-2021
Time : 16:00:00
Speaker : Prof. Praveen Nahar
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

Many organizations attempt to solve one problem but realize that it is interconnected with many other issues and challenges. Various stakeholders may have different needs or concerns, and it is not easy to make sense of them all. Design thinking (or designerly way of thinking) is an iterative framework that is used to understand the need, context, users, challenge assumptions, redefine problems and create innovative solutions to prototype and test, it is very useful in the situations where the problems which are ambiguous, unknown, and not so well defined.The presentation focuses on design, design thinking & innovation, its characteristics, skill sets, mindsets, and process framework with some case studies from Product Design and allied fields. It will also touch upon its possible contribution to scientific research in strategic planning processes and unknown territories.

Date : 20-01-2021
Time : 16:00:00
Speaker : Dr. Mrutyunjay Mohapatra
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

Most of these natural disasters (about 80%) are hydro-meteorological in nature. They include cyclones, floods, droughts, landslides, heat wave, cold wave, thunderstorms, and tornadoes. The risk management of these natural disasters includes several steps based on its severity and impact: (i) hazard analysis, (ii) vulnerability analysis, (iii) preparedness and planning, (iv) early warning, (v) prevention and mitigation. The early warning component includes: (i) skill in monitoring and prediction of natural hazards, (ii) effective generation and dissemination of products for warning, (iii) coordination with emergency response units, and (iv) public awareness and perception about the credibility of the official predictions and warnings. Though there have been significant improvement in multi-hazard monitoring and warning system in recent years due to various initiatives of Ministry of Earth Sciences (MoES) / India Meteorological Department (IMD) and policy frame work of Government of India, there is still scope for improving (i) mesoscale hazard detection and monitoring, (ii) spatial and temporal scale of forecasts through technological upgradation, (iii) impact based forecast and sectoral applications, (iv) warning communication to last mile. All these aspects will be discussed with respect to current status, existing gap areas, and future scope.

Date : 06-01-2021
Time : 16:00:00
Speaker : Prof. Ravi Shankar Nanjundiah
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

The Indian Summer Monsoon governs the pulse of this country. It is known to vary at various scales. In this talk, we will discuss the mean monsoon and its variability at various scales ranging from within the season at extremely short scales (<10 days) commonly known as the synoptic scale, the intraseasonal variability (10-60 days), and from season-to-season (commonly known as interannual variability). In addition, we will briefly discuss some global phenomena that modulate the strength of monsoon, such as the El-Nino. We will also examine if this El-Nino and Monsoon linkage fluctuates with time. Additionally, we will also examine if the strength of intraseasonal variability also fluctuates and whether anthropogenic factors also affect it. Finally, we will also examine if the monsoon has fluctuations from decade-to-decade and factors that could cause this decadal variability.

Date : 23-12-2020
Time : 16:00:00
Speaker : Prof. S. Gurubaran
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

A plethora of wave phenomena occurs in the Earth’s atmosphere encompassing a multitude of spatial and temporal scales. Among their several manifestations in the upper layers of the atmosphere, a well-marked dynamical feature is the internal bore. A spectacular wave feature in the heights between 85 and 100 km involving an altitude dependent bright or dark wavefront followed by phase-locked crests and troughs was first reported by Mike Taylor and his coworkers in 1995 through all-sky airglow imaging observations that was later interpreted as a mesospheric bore. Since then, a number of ground and space-based investigations of this intriguing wave dynamical feature have been reported. We have analogs for the mesospheric bores in other atmospheric regions like the morning glory and tropospheric bores and also in channel bores that have been explained by the hydraulic jump theory. The mesospheric bores are occasionally observed in airglow emissions as a steep front followed by undulations or a turbulent regime behind. These bores have their origin in stable atmospheric layers characterized by temperature inversion (thermal duct) or favourable wind systems (Doppler duct). Atmospheric gravity waves propagating through those ducts can undergo amplitude steepening, resulting in bores with phase-locked crests and troughs behind (undular bore). The damping of waves behind the fronts can lead to turbulence (turbulent bore) on certain occasions. Bore-like fronts are also seen in noctilucent clouds at high altitudes. This talk will introduce this exciting subject of internal bores in the mesosphere and present some of the fascinating observational results obtained from different platforms in the recent past. The challenges in understanding the mechanisms underlying this phenomenon essentially lie in the sparsity of observational knowledge about the environmental or the background atmospheric parameters. This talk will highlight those challenges as well.

Date : 23-12-2020
Time : 16:00:00
Speaker : Prof. S. Gurubaran
Area : DEAN'S OFFICE
Venue : ONLINE

Abstract

A plethora of wave phenomena occurs in the Earth’s atmosphere encompassing a multitude of spatial and temporal scales. Among their several manifestations in the upper layers of the atmosphere, a well-marked dynamical feature is the internal bore. A spectacular wave feature in the heights between 85 and 100 km involving an altitude dependent bright or dark wavefront followed by phase-locked crests and troughs was first reported by Mike Taylor and his coworkers in 1995 through all-sky airglow imaging observations that was later interpreted as a mesospheric bore. Since then, a number of ground and space-based investigations of this intriguing wave dynamical feature have been reported. We have analogs for the mesospheric bores in other atmospheric regions like the morning glory and tropospheric bores and also in channel bores that have been explained by the hydraulic jump theory. The mesospheric bores are occasionally observed in airglow emissions as a steep front followed by undulations or a turbulent regime behind. These bores have their origin in stable atmospheric layers characterized by temperature inversion (thermal duct) or favourable wind systems (Doppler duct). Atmospheric gravity waves propagating through those ducts can undergo amplitude steepening, resulting in bores with phase-locked crests and troughs behind (undular bore). The damping of waves behind the fronts can lead to turbulence (turbulent bore) on certain occasions. Bore-like fronts are also seen in noctilucent clouds at high altitudes. This talk will introduce this exciting subject of internal bores in the mesosphere and present some of the fascinating observational results obtained from different platforms in the recent past. The challenges in understanding the mechanisms underlying this phenomenon essentially lie in the sparsity of observational knowledge about the environmental or the background atmospheric parameters. This talk will highlight those challenges as well.