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November 14, 2020
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November 17, 2020
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16th November Current Affairs

Superconductivity at Room Temperature

In News:

Recently, researchers have created a material that is superconducting at room temperature, however, it only works at a pressure of 267 Gigapascals (GPa), which is equivalent to about three-quarters of pressure at the centre of Earth (360 GPa).

Key Points:

Material Used: A mixture of carbon, hydrogen and sulfur was put in a microscopic niche carved between the tips of two diamonds (diamond anvil) and laser light was used on them to trigger chemical reactions.

Process:

As the experimental temperature was lowered, resistance to a current passed through the material dropped to a vanishingly small value below the critical temperature (Tc).

The transition of the sample to become superconductive occurred the best at transition temperature of around 15°C at 267 GPa.

Verification: To verify that this phase was indeed a superconductor, the group ascertained that the magnetic susceptibility of the superconductor was that of a diamagnet.

A superconducting material kept in a magnetic field expels the magnetic flux out its body when cooled below the critical temperature and exhibits perfect diamagnetism.

It is also called the Meissner effect which simply means that magnetic lines do not pass through superconductors in a magnetic field.

Superconductors:

A superconductor is a material that can conduct electricity or transport electrons from one atom to another with no resistance.

No heat, sound or any other form of energy would be released from the material when it has reached critical temperature (Tc), or the temperature at which the material becomes superconductive.

The critical temperature for superconductors is the temperature at which the electrical resistivity of metal drops to zero.

Prominent examples include aluminium, niobium, magnesium diboride, etc.

Applications:

From magnetic resonance imaging (MRI) machines, low-loss power lines, ultra powerful superconducting magnets to mobile-phone towers.

Researchers are also experimenting with them in high-performance generators for wind turbines.

Limitations:

Their usefulness is still limited by the need for bulky cryogenics (production of and behavior of materials at very low temperatures) as the common superconductors work at atmospheric pressures, but only if they are kept very cold.

Even the most sophisticated ones like copper oxide-based ceramic materials work only below −140°C.

Significance of the Research:

If researchers can stabilise the material at ambient pressure, applications of superconductivity at room temperatures could be achieved and will be within reach.

Superconductors that work at room temperature could have a big technological impact, for example in electronics that run faster without overheating.

Diamagnetism:

It is a very weak form of magnetism that is induced by a change in the orbital motion of electrons due to an applied magnetic field.

This magnetism is non-permanent and persists only in the presence of an external field.

The magnitude of the induced magnetic moment is very small, and its direction is opposite to that of the applied field.

Meissner Effect:

When a material makes the transition from the normal to the superconducting state, it actively excludes magnetic fields from its interior and this is called the Meissner effect.

This constraint to zero magnetic fields inside a superconductor is distinct from the perfect diamagnetism which would arise from its zero electrical resistance.

Maritime Vision 2030

In News:

Recently, the Union Minister of State for Shipping has inaugurated the Direct Port Entry (DPE) facility of V O Chidambaranar Port Trust (VOCPT).

Key Points:

The state-of-the-art DPE facility is created inside the Truck Parking Terminal which was developed under the ‘Sagarmala’ for issuing customs clearance of export cargo.

The IT-enabled infrastructure at the ports will make Indian ports, world-class ports aligning with the ‘Maritime Vision 2030’ of the Ministry of Shipping.

Significance:

It will reduce logistics cost and increase the velocity of the cargo.

It would enable direct movement of containers from factories, without intermediate handling at any container freight stations (CFSs), on a 24×7 basis.

It will help in increasing Ease of Doing Business for the exporters, as the facility will bring efficiency and reduce dwell time, lower tariff cost and improve the competitiveness of shippers in international trade.

Maritime India Vision 2030:

It is a ten-year blueprint for the maritime sector which will be released by the Prime Minister of India at the Maritime India Summit in November 2020.

It will supersede the Sagarmala initiative and aims to boost waterways, give a fillip to the shipbuilding industry and encourage cruise tourism in India.

Policy Initiatives and Development Projects:

Maritime Development Fund: A Rs. 25,000-crore fund, which will provide low cost, long-tenure financing to the sector with the Centre contributing Rs. 2,500 crore over seven years.

Port Regulatory Authority: A pan-India port authority will be set up under the new Indian Ports Act (to replace the old Indian Ports Act 1908) for enabling oversight across major and non-major ports, enhance institutional coverage for ports and provide for structured growth of the ports sector to boost investor confidence.

Eastern Waterways Connectivity Transport Grid project: It will aim to develop regional connectivity with Bangladesh, Nepal, Bhutan and Myanmar.

Riverine Development Fund: Calls for extending low cost, long-term financing for inland vessels with the support of a Riverine Development Fund (RDF) and for extending the coverage of the tonnage tax scheme (applicable to ocean-going ships and dredgers) to inland vessels also to enhance the availability of such vessels.

Rationalisation of Port Charges: It will make them more competitive, besides doing away with all hidden charges levied by ship liners to bring in more transparency.

Promotion of Water Transport: For decongestion of urban areas, and developing waterways as an alternative means of urban transport.

Tectonically Active Zone of Himalayas

In News:

Recently, a group of scientists from the Wadia Institute of Himalayan Geology (WIHG), Dehradun have found that the Indus-Tsangpo Suture Zone (ITSZ) of Himalayais tectonically active.

Details:

The suture zone of Himalaya was conventionally thought to be locked.

WIHG is an autonomous institute under the Department of Science and Technology (DST), Government of India.

Tectonics is the scientific study of the deformation of the rocks that make up the Earth’s crust and the forces that produce such deformation.

It deals with the folding and faulting associated with mountain building, the large-scale, gradual upward and downward movements of the crust and sudden horizontal displacements along faults.

Key Points:

Geological Features that Support the Finding:

Sedimentary beds are tilted and thrust broken.

Rivers are associated with uplifted terraces.

Bedrock shows brittle deformation at much shallower depths.

These deformed geological features were dated using the technique of Optically Stimulated Luminescence (OSL) and data of seismicity and denudation rate was also reviewed.

Optically-Stimulated Luminescence: It is a late quaternary (geological time period that encompasses the most recent 2.6 million years) dating technique used to date the last time quartz sediment was exposed to light. As sediment is transported by wind, water or ice, it is exposed to sunlight and zeroed of any previous luminescence signal.

Seismicity: It is the worldwide or local distribution of earthquakes in space, time, and magnitude. More specifically, it refers to the measure of the frequency of earthquakes in a region.

Denudation: It is a long term process in which the wearing and tearing of the surface of the Earth take place. It includes all those processes that lower relief and acts both chemically (chemical weathering) and physically (mechanical weathering).

The region of the ITSZ has been neo-tectonically active since the last 78000-58000 years.

The ITSZ is a suture zone in the Ladakh region and marks the limit of the Indian plate where it collides with the Eurasian plate and is subducted below the latter.

The ITSZ can be traced for more than 200 km and a wide variety of rock association along the ITSZ indicates that the collision at the plate boundary was of very complex nature.

The ITSZ was conventionally believed to be a locked zone till now.

This will have major implications in terms of earthquake study, prediction, understanding the seismic structure of the mountain chains well as its evolution.

Suture Zones:

A suture zone is a linear belt of intense deformation, where distinct terranes, or tectonic units with different plate tectonic, metamorphic, and paleogeographic histories join together.

These zones also provide the only record of deep oceanic crust and of ancient seafloor processes for roughly the first 90% of Earth’s history.

Their study provides a means to understand the end-product of plate tectonic processes in time and space. In plate tectonics, sutures are seen as the remains of subduction zones together with the terranes possibly representing fragments of different tectonic plates.

The suture zone is often represented on the surface by a mountain range comprising intensely deformed rocks.

The Iapetus Suture from Great Britain, which is now concealed beneath younger rocks, and Indo-Tsangpo Suture well exposed in the Himalayas are some of the best examples of suture zones.