Daily News: Science, Defense, Agriculture, Economy & World

Current Affairs Analysis: 26 February 2024

The Hindu, IE, PIB and Others

A) Science and Technology, Defence and Space

1.Cryogenic Technology and India

Context: Recently, the Indian Space Research Organisation (ISRO) successfully completed human-rating of the CE-20 rocket engine. Human-rating refers to rating a system that is capable of safely transporting humans.


CE-20 Cryogenic Engine

  • The CE-20 is the first indigenously developed cryogenic engine ISRO developed to use in the third stage of its launch vehicle Geosynchronous Satellite Launch Vehicle Mk III (GSLV Mk III), now called the Launch Vehicle Mark-3 (LVM-3).
  • The CE-20 is important to ISRO successfully realising its Gaganyaan Mission – India’s mission to launch an Indian astronaut to space onboard an Indian rocket.
  • LVM-3 rockets using the CE-20 in the third stage — where the first stage comprises two solid-fuel boosters and the second stage, two liquid-fuelled Vikas 2 engines — have already launched the Chandrayaan-2 and -3 missions and payloads of the commercial OneWeb mission in 2022.
  • Only six countries including India, the United States, France (European Space Agency), Russia, China, and Japan have developed their own cryogenic engines.

What is a Cryogenic Engine?

  • A cryogenic engine is a type of rocket engine that uses liquefied gasses as fuel and oxidizers.
  • The term cryogenic refers to the fact that these liquefied gasses must be kept at cryogenic temperatures, that is, very low temperatures (below -150 degree Centigrade)
  • A cryogenic engine typically employs Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) as propellants, instead of conventional rocket fuels.
  • A cryogenic rocket stage is more efficient and provides more thrust (force) for every kilogram of propellant it burns compared to solid and earth-storable liquid propellant rocket stages.
  • Specific impulse (a measure of the efficiency) achievable with cryogenic propellants (liquid Hydrogen and liquid Oxygen) is much higher compared to earth storable liquid and solid propellants, giving it a substantial payload advantage.
  • However, the cryogenic stage is technically a very complex system compared to solid or earth-storable liquid propellant stages due to its use of propellants at extremely low temperatures and the associated thermal and structural problems.

How does a Cryogenic Engine Work?

  • As opposed to electric motors, whose power comes from rotating motion, cryogenic engines are reaction engines.
  • In order to work, they throw mass in one direction and rely on the reaction thrust in the opposite direction.

Advantages and Disadvantages of Cryogenic Engines

  • Among the main advantages of cryogenic engines are:
  • More environmentally-friendly than other options 
  • Non-toxic and non-corrosive
  • Able to reduce the cost of launch operations
  • Efficient and high-specific impulse
  • Safer than other options in terms of ground safety, they’re non-hypergolic 
  • The disadvantages of this type of engine include:
  • Liquid Hydrogen presents a low density
  • Their cryogenic storage requires of complex equipment that must be carefully tailored by experts
  • Presents the need for devising an ignition system
  • Note: A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other without any external aid (such as a spark).

Why do engineers prefer to use liquid fuels fr rocket motors?

  • Engineers prefer to use liquid fuels for rocket motors because they are less bulky and flow better than solid fuels.
  • Using hydrogen as fuel is also desirable because when it is combusted, it generates the highest exhaust velocity. This is why hydrogen is a desirable fuel for rocket motors.
  • However, hydrogen in liquid form is not well-behaved: it needs to be maintained at -253 degrees C (and the liquid oxygen at -184 degrees C) and leaks very easily.
  • Engineers need special equipment to store and transport liquid hydrogen and special engines that can use it to power a rocket. These are cryogenic engines.

Gaganyaan: India’s Human Space Flight Programme (HSP)

  • Gaganyaan, the human space flight Programme (HSP), seeks to put a three-man Indian crew in a Low Earth Orbit (LEO), at a height of about 400 km in space. They will circle earth over three to seven days.
  • ISRO has also received inputs for the mission from Glavkosmos, a subsidiary of Russian State Space Corporation Roscosmos, as well as the French government’s National Centre for Space Studies (CNES).
  • Four pilots of the Indian Air Force are currently training at the Gagarin Research and Test Cosmonaut Training Centre (GCTC) in Moscow, Russia.
  • When it achieves the mission, India would be the fourth nation to circle Earth after the Soviets, the Americans and the Chinese.

Why is GSLV Mk-III being used of Gaganyaan Mission?

  • ISRO will use Geosynchronous Satellite Launch Vehicle (GSLV Mk-III) vehicle to carry the heavier payload of the Gaganyaan.
  • The spacecraft carrying human beings, called crew module, is likely to weigh in excess of 5 to 6 tonnes.
  • ISRO’s main launch vehicle, the PSLV (Polar Satellite Launch Vehicle), which carried the Chandrayaan and Mangalyaan missions, can carry payloads that are barely up to 2 tonnes, and that too only to orbits at about 600 km altitude from the Earth’s surface.
  • For the Gaganyaan mission, ISRO has indigenously developed new technologies including a human-rated launch vehicle, crew escape systems, Pad Abort Test, a habitable orbital module, and a life support system.

Pad Abort Test

  • Its purpose is to safely parachute the future astronauts down in case their space vehicle develops snags while taking off.

2. Dengue: Causes and Treatment

Context: According to a new study, primary dengue virus infections constitute a substantial fraction of severe disease cases and fatalities.

  • Patients who are infected by any dengue virus for the first time are known as cases of primary dengue infection.
  • Patients who were previously infected by another dengue virus and then present with infection from a new serotype are known as cases of secondary dengue infection.
  • Serotype is a way of grouping cells or microorganisms, such as bacteria or viruses, based on the antigens or other molecules found on their surfaces.
  • An antigen is any substance that causes our immune system to produce antibodies against it. Majority of antigens are proteins but some are carbohydrates, lipids, and nucleic acids.


  • Dengue is essentially a tropical disease that occurs in the countries around the Equator; hot weather and intermittent rainfall favour the sustenance of Aedes aegypti — the vector transmitting the dengue virusand Aedes albopictus, a minor contributor.
  • Dengue is an endemic disease, which means that it occurs regularly, in tropical regions of the world.
  • The dengue virus is transmitted to humans via the bite of an infected mosquito. Only a few mosquito species are vectors for the dengue virus.
  • In rare events, dengue can be transmitted during organ transplantations or blood transfusions from infected donors. 
  • Vectors are animals and microorganisms that transmit different diseases. The most common vectors are arthropods, which are invertebrate animals with an external skeleton called an exoskeleton. Arthropods include mosquitoes, ticks, lice, flies, and fleas. 
  • Once infected with dengue, the mosquito will remain infected with the virus for its entire life.
  • Both male and female mosquitoes feed on plant nectars, fruit juices, and other plants sugars as their main energy source.
  • Why, then, do mosquitoes bite humans? Female mosquitoes require blood to produce eggs, so they bite humans. 
  • How does the virus travel from the mosquito’s salivary glands into a human? When taking a blood meal, an infected female mosquito injects its saliva into the human host to prevent the host’s blood from clotting and to ease feeding. This injection of saliva infects the host with the dengue virus.
  • Female mosquitoes generally lay their eggs above the water line inside containers that hold water. 
  • Aedes aegypti mosquitoes have adapted so that their eggs can survive dry conditions for several months. If eggs are laid in a dry container, new mosquitoes only develop when the container is filled with water.
  • This adaptation has made it very difficult to eliminate mosquito populations completely.
  • In many areas of the world, dengue outbreaks occur every year during the rainy season, when conditions are perfect for mosquito breeding.
  • The dengue virus is spread through a human-to-mosquito-to-human cycle of transmission.
  • When a mosquito bites a person who has dengue virus in his or her blood, the mosquito becomes infected with the dengue virus.
  • An infected mosquito can later transmit that virus to healthy people by biting them.
  • Dengue cannot be spread directly from one person to another, and mosquitoes are necessary for transmission of the dengue virus.
  • Aedes mosquitoes cannot fly beyond a hundred metres. Hence, keeping the ambience clean can help prevent their breeding.
  • Further, these mosquitoes bite during the daytime, so keeping the windows shut in the day hours is also useful.
  • Dengue is mostly an asymptomatic infection, and only a very few develop severe disease.
  • Fluid management is the cornerstone in the management of severe diseases like dengue hemorrhagic fever and dengue shock syndrome.

Role of platelets in dengue infection

  • Contrary to the common belief, platelet transfusions are not needed even in cases of active bleeding, as per the guidelines of the World Health Organization (WHO).
  • Coagulation abnormalities are not due to a reduction in the number of platelets alone. This is why the WHO recommends fresh whole blood or packed cell transfusion in the event of bleeding. The platelet count will increase automatically as fever subsides.

Debug Fresno Project

  • The project, called Debug Fresno, is being undertaken by Verily, a subsidiary of Alphabet, Google’s holding company.
  • The goal is to cut the numbers of Aedes aegypti mosquitoes which are responsible for spreading zika, dengue and chikungunya.
  • The male mosquitoes are bred and infected with Wolbachiaa bacterium that is naturally found in at least 40% of all insect species. 
  • The bacterium used to sterilise mosquitoes “is not known” to infect humans.
  • In a phenomenon called cytoplasmic incompatibility, matings between Wolbachia-infected males and uninfected females result in embryo lethality or low hatch rates.

Dengue Vs Chikungunya

  • Dengue and Chikungunya are viral diseases with very similar symptoms.
  • The Aedes aegypti is more likely to spread dengue and the Aedes albopictus, the chikungunya virus. However, both types of mosquitoes can spread both diseases.
  • It is also possible for a patient to have Dengue and Chikungunya at the same time. 
  • The most distinguishing feature of Dengue is bleeding.
  • Chikungunya is rarely fatal, but dengue can be.

Knowledge Corner

  • Aedes aegypti is a known vector of several other viruses as well.
Disease caused by Aedes MosquitoType of Pathogen
Chikunguniya Dengue Lymphatic Filariasis Rift Valley Fever Yellow Fever ZikaVirus Virus Parasite Virus Virus Virus

B) Geography: India and World

3. India-MiddleEast-Europe Economic Corridor (IMEC)

  • Context: As the Red Sea crisis enters its fourth month, global supply chains are increasingly grappling with inflated freights, delayed vessel schedules, and product shortages.
  • In this context, there’s a pressing need to underscore the significance of the India-Middle East-Europe Economic Corridor (IMEC).


Why is the Red Sea route important?

  • The Red Sea owes its strategic importance for global trade to the Bab el-Mandab Strait which lies between Yemen and Djibouti.
  • It is one of the world’s busiest cargo and oil transit points with almost 12% of international merchandise trade passing through it.
  • An immediate consequence of the Red Sea conflict has been that major container and oil carriers have been forced to re-route shipments via the Cape of Good Hope.
  • The re-routing has led to rising ocean freight, inflated insurance costs, and longer voyage times leading to delays and shortage of products.

How has It Affected India?

  • India’s trade with European and North African countries flows entirely through the Red Sea route which is almost 24% of its exports and 14% of its imports.
  • As global supply chains are battling delayed shipments and rising costs, China is actively projecting China-Europe freight trains, which are part of the Belt and Road Initiative (BRI), as an alternate route, which India does not support.
  • One of the major reasons why India doesn’t support BRI is because one of the parts of the project, the China-Pakistan Economic Corridor (CPEC), passes through the Indian territories occupied illegally by Pakistan.

What About the IMEC?

  • In September 2023, seven countries and the European Union announced plans to create the India–Middle East–Europe Economic Corridor (IMEC), negotiated on the margins of the G20 Summit in New Delhi. 
  • IMEC partners – the EU, France, Germany, India, Italy, Saudi Arabia, the United Arab Emirates (UAE) and the US – signed a memorandum of understanding at the G20 Summit stating that they will cooperate to establish two corridors, one connecting Europe to the Gulf and the other connecting the Gulf to India.
  • The corridors will consist of rail links, electrical and data cables, and pipelines for exporting hydrogen. They will also connect with Israel and Jordan, though these countries did not sign the IMEC agreement.
  • However, the Israel-Palestine conflict has put a pause on the normalisation of Arab-Israel relations which is a key element of the multi-nation initiative.
  • Another major challenge is the vulnerability of the Strait of Hormuz. The entire trade of the IMEC architecture flows through the Strait of Hormuz and with Iran’s proximity and control over the strait, the risk of disruptions remain very high.
  • Some experts argue that the Strait of Hormuz problem can be avoided by including Oman in the IMEC architecture and keeping the supply chain away from Iran’s reach.
  • However, that would mean further delays, as new ports and railway links will have to be developed across Oman connecting it to Saudi Arabia.

Knowledge Corner

a) Strait of Hormuz

  • The Strait of Hormuz is the world’s single most important oil passageway, forming a chokepoint between the Arabian Gulf and the Gulf of Oman.
  • It lies between Oman and Iran, linking the sea passage from the countries on the Gulf (Iraq, Kuwait, Saudi Arabia, Bahrain, Qatar and the United Arab Emirates) with the Arabian Sea and beyond.
  • The strait is 55 to 95 km wide and separates Iran (north) from the Arabian Peninsula (south).

b) Bab el-Mandeb

  • Bab el-Mandeb, which is just 29-km wide at its narrowest point, is a strategically important strait given its location.
  • It is a strait between Arabia (northeast) and Africa (southwest) that connects the Red Sea (northwest) with the Gulf of Aden and the Indian Ocean (southeast). C
  • losure of the waterway would prevent tanker traffic bound from the Persian Gulf from reaching the Suez Canal, primarily impairing exports to Europe.

C) Agriculture, Environment and Biodiversity

4. National Air Quality Index (AQI)

  • Context: The National Green Tribunal has directed 53 cities which witnessed deterioration in air quality to submit a complete report on the contribution of each polluting source and measures taken to reduce pollution.
  • The tribunal was hearing the issue of air quality deterioration in different cities across India as reflected in the Air Quality Index (AQI) maintained by the Central Pollution Control Board.


National Air Quality Index (AQI)

  • AQI is an initiative under ‘Swachh Bharat’ and acts as ‘One Number – One Colour-One Description’ to judge the air quality for common man.
  • The Central Pollution Control Board (Ministry of Environment, Forest and Climate Change) calculates the AQI.
  • AQI is an index for reporting air quality on a daily basis.
  • The purpose of the AQI is to help people know how the local air quality impacts their health.
  • There are six AQI categories of AQI, namely:
  • Good (0-50),
  • Satisfactory (51-100),
  • Moderately polluted (101-200),
  • Poor (201-300),
  • Very Poor (301-400), and
  • Severe (401-500). 
  • The Air Quality Index (AQI) is the weighted average of different pollutants and a lower value of AQI means better air quality.
  • It considers eight pollutants [PM10, PM2.5, Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Carbon monoxide (CO), Ozone (O3), Ammonia (NH3) and Lead (Pb)] for which short-term (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed.
  • AQI is based on 24 hour or 8 hour average pollutant concentration and not on hourly concentration.
  • All the criteria pollutants may not be monitored at all the locations. Overall AQI is calculated only if data are available for minimum three pollutants out of which one should necessarily be either PM2.5 or PM10. 

5. Olive Ridley Sea Turtles

  • Context: Failure to strictly implement the prohibition of fishing trawlers within a 20-kilometre radius from the high tide line at the mass nesting sites of Gahirmatha, Devi river mouth and Rushikulya is the primary cause of the deaths of a large number of Olive Ridley sea turtles along the Odisha coast each year.


  • The Olive Ridley turtles are the smallest and most abundant of all sea turtles found in the world.
  • They inhabit warm waters/ tropical regions of the Pacific, Atlantic and Indian oceans.
  • These turtles, along with the Kemps Ridley turtle, are best known for their unique mass nesting called Arribada, where thousands of females come together on the same beach to lay eggs.
  • Though found in abundance, their numbers have been declining over the past few years, and the species is recognized as Vulnerable under the International Union for Conservation of Nature’s Red list.
  • Olive ridley turtles are carnivores and these turtles spend their entire lives in the ocean.

Nesting Places in India

  • The coast of Orissa in India is the largest mass nesting site for the Olive-Ridley which happens during the months of October to April, followed by the coasts of Mexico and Costa Rica.
  • The 480-km-long Odisha coast has three arribada beaches at Gahirmatha, the mouth of the Devi river, and in Rushikulya, where about 1 lakh nests are found annually.
  • According to wildlife experts, in India, while states like Maharashtra, Goa, and the offshore Andaman Islands witness sporadic nesting of olive ridley turtles, Odisha is the only state in India that sees mass nesting of olive ridley turtles.
  • Both the mass nesting hotspots (Gahirmatha and Rushikulya) are located close to the biodiversity-rich regions of Odisha.
  • While the Gahirmatha site is adjacent to the Bhitarkanika Wildlife Sanctuary, Rushikulya is close to the Chilika Lake, Asia’s largest brackish water lagoon.
  • In India, the turtles have also been found to nest in Tamil Nadu, Andhra Pradesh and parts of the Konkan coast.
  • More recently, a new mass nesting site has been discovered in the Andaman and Nicobar Islands.
  • In the Andaman and Nicobar Islands, olive ridley and leatherback turtles often share nesting beaches, while hawksbill and green turtles share beaches.


  • Sea turtles generally return to their natal beach, or where they were born, to lay eggs as adults.
  • The eggs, laid in nests dug along the beach, incubate on their own with the help of the heat from the sand. (No need of mother to sit on eggs).
  • Depending on the temperature of the sand, the eggs hatch in about 45 to 60 days.
  • Studies have found three main factors that damage Olive Ridley turtles and their eggs —
  • heavy predation of eggs by dogs and wild animals,
  • indiscriminate fishing with trawlers and gill nets, and
  • beach soil erosion.
  • The rain can affect the eggs of turtle incubating under the sand in the following ways:
  • Reduction of temperature in the nests.
  • Tightening the sand covering the eggs.
  • Sex determination of the hatchlings.

Species of sea turtles in India

  • Five species of sea turtles are known to inhabit Indian coastal waters and islands. These are:
  • Olive Ridley (Vulnerable),
  • Green (Endangered),
  • Hawksbill (Critically Endangered),
  • Loggerhead (Vulnerable) and 
  • Leatherback (Vulnerable).
  • These five species are found worldwide, mainly in tropical and subtropical waters.
  • Except the Loggerhead, the remaining four species nest along the Indian coast.
  • Other than these five species, there are two more types of sea turtles that have restricted ranges.
  • Kemp’s Ridley is found mainly in the Gulf of Mexico and the flatback turtle around northern Australia and southern Papua New Guinea. 
  • The eastern coastline is the feeding area for Olive Ridley, juvenile Hawksbills and Green turtles.
  • All five species of sea turtles found in India are included in Schedule I of the Indian Wildlife Protection Act, 1972 (which bans consumption of turtle meat and eggs by all except for indigenous tribal communities, including the Onges and Shompen, in the Andaman and Nicobar Islands), and in the Appendix I of the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES), which prohibits trade in turtle products by signatory countries.
  • The hawksbill turtles are prized in the illicit wildlife trade for their beautiful shells.
  • Climate change has an impact on turtle nesting sites — it alters sand temperatures, which affects the sex of hatchlings. 
  • The sex of the Olive Ridley turtles is determined by the temperature at which they are hatched.
  • A male turtle is born if the egg hatches at a temperature below 29 degrees Celsius.
  • Above that, the hatchling is a female. 

Role in marine ecosystem

  • Sea turtles, especially the leatherback, keep jellyfish under control, thereby helping to maintain healthy fish stocks in the oceans.
  • The Green turtle feeds on sea grass beds and by cropping the grass provide a nursery for numerous species of fish, shellfish and crustaceans.
  • The Hawksbill feeds on sponges in the reef ecosystem and opens up crevices for other marine life to live in.
  • As they feed in one location and migrate to a distant beach to breed, sea turtles are regarded as important biological transporters of nutrients and energy between marine and terrestrial ecosystems.

Gahirmatha Marine Wildlife Sanctuary

  • The Gahirmatha Marine Wildlife Sanctuary extends from Dhamara river in the north to Brahmani river mouth in the south and is famous for its nesting beach for Olive Ridley Turtles.
  • Gahirmatha in Kendrapara district, 150 km from the State capital Bhubaneswar, is the world’s largest rookery for Olive Ridley sea turtles.
  • These turtles travel all the way from South Pacific Ocean to breed on the coast of Gahirmatha.
  • However, once known as a safe nesting ground on India’s east coast, a nearly 30-km long coastline in the Godavari estuary has been witnessing a sharp fall in the arrival of Olive Ridley turtles during the breeding season as large numbers of them are trapped by high-speed fishing boats on the Andhra coast.
  • The entire rookery, including the Coringa Wildlife Sanctuary, is part of the rare and ecologically sensitive Godavari mangrove system.

Do you know?

  • Some other countries with Olive Ridley nesting sites are:
  • Mexico
  • Costa Rica
  • Brazil
  • Kenya
  • Australia

D) Economic Developments: India and World

6. Current Account–Savings Account (CASA) Deposit

  • Context: CASA (current account–savings account) deposit ratio has declined by around 200 bps since the March quarter of FY22.


  • Current account savings accounts (CASA) are a type of non-term deposits, meaning they do not have a specific maturity or expiration date.
  • A CASA pays a lower interest rate than term deposits (which commits the customer’s money for a certain period of time), such as certificates of deposit, and is thus a cheaper source of income for the financial institution.
  • The money deposited can be withdrawn or paid out at any time.

E) International Relations

7.  Economic Community of West African States (ECOWAS)

  • Context: West Africa’s regional bloc ECOWAS said that it was easing sanctions imposed on Guinea and Mali, a day after announcing a similar decision for Niger, another country under military rule.


  • ECOWAS has suspended all three countries — and Burkina Faso — from membership of the bloc because of the military takeovers there.
  • The ECOWAS changed its approach to renew dialogue with military regimes among its members after Mali, Niger and Burkina Faso announced their intention to leave the bloc.
  • The three countries have formed an alliance, severed ties with traditional security partner France and forged closer relations with Russia, which is seeking greater influence in Africa.


  • The Heads of State and Government of fifteen West African Countries established the Economic Community of West African States (ECOWAS) when they signed the ECOWAS Treaty in 1975 in Lagos, Nigeria.
  • The Member States are Benin, Burkina Faso, Cabo Verde, Côte d’Ivoire, The Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Niger, Nigeria, Sierra Leone, Sénégal and Togo.

F) Miscellaneous

8. What are Blanets?

  • A blanet is a member of a hypothetical class of exoplanets that directly orbit black holes.
  • Blanets are fundamentally similar to other planets; they have enough mass to be rounded by their own gravity, but are not massive enough to start thermonuclear fusion and become stars.
  • In 2019, a team of astronomers and exoplanetologists showed that there is a safe zone around a supermassive black hole that could harbor thousands of blanets in orbit around it.


  • The 5th edition of Joint Military Exercise ‘DHARMA GUARDIAN’ between the Indian Army and the Japan Ground Self Defence Force commenced recently at Mahajan Field Firing Ranges in Rajasthan.
  • Exercise ‘DHARMA GUARDIAN’ is an annual exercise and conducted alternatively in India and Japan.
  • Aim of the Exercise is to foster Military Cooperation and enhance combined capabilities to execute joint operations in semi-urban environment.
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