Vagir All about the Kalvari class submarine commissioned by Indian Navy (GS Paper 3, Defence)
Why in news?
- The Indian Navy is set to commission the fifth scorpene-class submarine Vagir.
- The commissioning of the submarine, built under the Project-75, is set to encourage the Navy's combat capability at a time when China has been increasing its presence in the Indian Ocean region.
Project-75:
- The Project-75 includes indigenous construction of six submarines of Scorpene design.
- The submarines are being constructed at Mazagon Dock Shipbuilders Limited (MDL), Mumbai under a collaboration with the Naval Group of France.
- Four Submarines of the ongoing Project-75 Scorpene programme at MDL, Kalvari, Khanderi, Karanj and Vela have been commissioned into the Indian Navy.
- The fifth submarine Vagir is being commissioned today, whilst the sixth and last submarine 'Vagsheer' will also undergo sea trials after launching.
Vagir:
- The erstwhile Vagir was commissioned on November 1, 1973 and undertook numerous operational missions including deterrent patrols. The submarine was decommissioned in January 2001 after serving the nation for about three decades.
- Scorpene submarines can undertake various types of missions i.e anti-surface warfare, anti-submarine warfare, intelligence gathering, mine laying, area surveillance etc.
- The Scorpene submarines are extremely potent platforms. They have advanced stealth features and are also equipped with long range guided torpedoes as well as anti-ship missiles. They also have a state of the art SONAR and sensor suite permitting outstanding operational capabilities.
- In addition, they also have advanced Permanent Magnetic Synchronous motor (PERMASYN) as its propulsion motor.
- The submarine is designed to operate in all theatres of operation, showcasing interoperability with other components of a Naval Task Force. It is a potent platform, marking a transformational shift in submarine operations.
What is the Leopard 2 tank, and how could it help Ukraine against Russia?
(GS Paper 3, Defence)
Why in news?
- Germany is under intense pressure to provide Ukraine with its Leopard 2 tanks, which could have a significant impact against the Russian invasion.
- European allies have already sent hundreds of modernised Soviet tanks to Ukraine since the war started nearly 11 months ago. But Ukraine has pleaded for more advanced military equipment to get the upper hand in the fight against Russia.
- Germany has not decided whether to allow its Leopard 2 tanks to be sent to Ukraine, U.S. Defense Secretary Lloyd Austin said after a U.S.-led meeting of Ukraine’s allies ended with no consensus.
What is a Leopard 2 tank?
- The Leopard 2 is one of the world’s leading battle tanks, used by the German Army for decades and by the militaries of more than a dozen other European nations, as well as by the armies of countries as far apart as Canada and Indonesia. It has seen service in conflicts in Afghanistan, Kosovo and Syria.
- The tank, which is powered by a diesel engine, features night-vision equipment and a laser range finder that can measure distance to an object, enabling it to better aim at a moving target while traveling over rough terrain.
- There are multiple iterations of the Leopard 2 with different features and designs.
How could the tank help Ukraine?
- Until now, both Ukraine and Russia have used Soviet-era tanks in battle, and the Leopards would offer a big step forward in capability.
- Ukraine’s government has been calling for tanks on top of earlier packages of military aid from allies in the United States and Europe that included aircraft, air defense systems to protect against Russian missile and drone attacks and longer-range artillery.
- Supplies of the Leopard 2 would help offset Russia’s superiority in artillery firepower, which aided Moscow in seizing two cities in eastern Ukraine’s Luhansk province over the summer.
- They could be of particular value as the war approaches its second year and Ukraine looks to reclaim lost territory and expects a Russian spring offensive.
What are the advantages of Leopards over other tanks?
- Britain has promised to supply Ukraine with 14 of its Challenger 2 tanks, and U.S. planned to supply nearly 100 Stryker combat vehicles, though it has not committed to sending American-made M1 Abrams tanks, which require constant upkeep and generally run on special fuel.
- The chief advantage of the Leopard 2 was the quantity that could be sent to Ukraine and the relative ease of repair and logistics.
- In addition, because several European countries use the vehicles, multiple nations could contribute either the tanks themselves, or spare parts, training capacity or logistics.
Why does Germany have to approve the transfer of Leopards owned by other countries?
- Re-exporting German-made tanks without it’s permission would be illegal.
- The contracts that a country signs to obtain weapons from German manufacturers or German military stocks require them to request a re-export license from the federal government should they wish to send such weapons to another country.
- The United States has similar requirements, as do other countries, including Switzerland.
Researchers combine natural squid tissues with synthetic polymers to develop hydrogel
(GS Paper 3, Science and Tech)
Why in news?
- Natural squid tissues and synthetic polymers were blended by scientists at Hokkaido University in Japan to create a robust hydrogel that closely resembles the special characteristics of biological tissues.
- There are numerous applications for hydrogels, which are polymer networks that contain a lot of water, including soft robotic parts, new sensing systems, and medical prosthetics.
Why it matters?
- Natural biological tissues exhibit unique properties essential for their functions, which researchers are seeking to replicate in hydrogels.
- Muscles, for example, in addition to strength and flexibility, have physical properties that vary in different directions and are built from a hierarchy of structures working together. Bones and blood vessels also display these features, known as hierarchical anisotropy.
- Unlike the natural tissues that researchers wish to mimic, most synthetic hydrogels have uniform properties in all directions and are structurally weak.
How gel was prepared?
- The manufacturing process begins with commercially available frozen squid mantle, the main outer part of a squid. In live squid, the mantle expands to take water into the body, and then strongly contracts to shoot water outwards as a jet.
- This ability depends on the anisotropic muscles within squid connective tissue. The researchers took advantage of the molecular arrangements within this natural system to build their bio-mimicking gel.
- Chemical and heat treatment of thin slices of the defrosted squid tissue mixed with polyacrylamide polymer molecules initiated formation of the cross-linked hybrid hydrogel.
- It has what is known as a double-network structure, with the synthetic polymer network embedded and linked within the more natural muscle fiber network derived from squid mantle.
Potential:
- The current proof-of-concept work should be just the start for exploring many other hybrid hydrogels that could exploit the unique properties of other natural systems.
- Jellyfish have already been used as a source of material for simpler single-network hydrogels, so are an obvious next choice for exploring hybrid double-network options.
- Possible applications include load-bearing artificial fibrous tissues, such as artificial ligaments and tendons, for medical use.
Way Forward:
- Further work by the team will explore the biocompatibility of the gels and investigate options for making a range of gels suitable for different uses.
