Syllabus

• Prelims & Mains – SCIENCE & TECHNOLOGY

Context: Big cities are yet to clear any land in half of their legacy landfill sites, with only 38% of the total dumped waste being remediated so far. It underscores the need for more effective strategies and resources to overcome the obstacles in waste remediation, and draws attention to the significance of waste-to-energy technologies.

Background: –

• While waste remediation involves processes that clean up and rehabilitate contaminated land, waste-to-energy technologies convert non-recyclable waste materials into usable forms of energy, such as electricity or heat.

Traditional to Modern Waste Management: Key Insights

• The Industrial Revolution (mid-18th century) marked the beginning of large-scale waste generation due to industrial production.
• Traditional waste management involved direct disposal into landfills, oceans, or remote areas, which is now unsustainable due to environmental impacts.
• Definition of Waste: According to the UN Statistical Division, waste refers to materials that are no longer useful for production, transformation, or consumption and are meant for disposal.
• Global Waste Generation: Currently, global waste production is 1.3 billion tonnes annually and is projected to rise to 2.2 billion tonnes by 2025, making waste management a critical global concern.

Waste-to-Energy Technologies:

• Waste-to-energy technologies serve two purposes: (a) managing large-scale waste generated from household, municipal and industrial activities and, (b) meeting the rising energy demands. Simply put, ‘waste-to-energy refers to a series of technologies that convert non-recyclable waste into some usable forms of energy’.
• They align with UN SDG 7 (Affordable and Clean Energy) and SDG 11 (Sustainable Cities and Communities) and promote the circular economy.

Conversion Processes:

• Thermochemical Technologies: Include incineration, pyrolysis, and gasification for energy recovery from waste.
  • Incineration: Common method for treating heterogeneous waste by burning it at high temperatures in a specific kind of furnace called incinerators. This technique is appropriate for wastes with high caloric value as well as for non-hazardous municipal waste.
  • Pyrolysis: Breaks down waste without oxygen to produce fuels (char, pyrolysis oil, syngas). It is an old technology that was used to produce charcoal from wood.
  • Gasification: Decomposes carbon-rich waste to produce syngas. Pyrolysis and gasification are better suited for homogenous waste types.
• Biochemical Technologies: Use biological processes for organic waste (kitchen/garden).
  • Anaerobic Digestion: is appropriate for organic waste where micro-organisms break down material in the absence of oxygen. One of the end-products is biogas. This method can occur naturally or can be engineered in bio-digesters and sanitary landfills.
  • Landfilling: Composting and landfilling involve burying of waste accompanied by deploying landfill gas recovery systems. Although landfilling is less expensive, it is environmentally detrimental due to the release of toxic and obnoxious gases.
• Waste-to-Energy in India:
  • The first plant was established in Delhi in 1987. As of 2022, India has 12 operational plants.
  • Despite policies from the Ministry of New and Renewable Energy, power generation from waste remains minimal, at just 554 MW (0.1% of total energy generated).
  • There is a perception that waste-to-energy plants have failed in India. Commonly cited reasons are administrative delays in getting approval as well local opposition This happened in the case of the Bandhwari plant proposed in Gurugram in Haryana in 2021. Other reasons include extremely heterogeneous, unsegregated and poor quality of waste which requires excessive pre-treatment and increases the fuel requirement making the entire process expensive and unviable.
  • Global best practices (e.g., Denmark’s hedonistic sustainability) could be adapted in India.

Source: Indian Express

 Syllabus

• Prelims – GEOGRAPHY

Context: The Amazon River, battered by back-to-back droughts fueled by climate change, is drying up, with some stretches of the mighty waterway dwindling to shallow pools only a few feet deep.

Background: –

• Water levels along several sections of the Amazon River, fell last month to their lowest level on record, according to figures from the Brazilian Geological Service.

About Amazon river

• The Amazon River, located in South America, is the second longest river in the world, after the Nile, with a length of approximately 6,400 kilometers.
• It flows through Peru, Colombia, and primarily Brazil, discharging into the Atlantic Ocean.
• The Amazon Basin, the largest drainage basin in the world, covers about 7 million square kilometers, accounting for nearly 40% of South America’s landmass.
• The extensive lowland areas bordering the main river and its tributaries, called várzeas (“floodplains”), are subject to annual flooding, with consequent soil enrichment; however, most of the vast basin consists of upland, well above the inundations and known as terra firme.
• More than two-thirds of the basin is covered by an immense rainforest, which grades into dry forest and savanna on the higher northern and southern margins and into montane forest in the Andes to the west.

Hydrological Significance:

• The Amazon carries more water than any other river on Earth, accounting for approximately 20% of the world’s fresh river water.
• It has the largest discharge of any river, with an average flow of about 209,000 cubic meters per second.
• The river is fed by over 1,000 tributaries, with the Rio Negro, Madeira, and Tapajós being the largest.

Biodiversity:

• The Amazon River and its surrounding rainforest support one of the most biodiverse ecosystems in the world.
• It is home to a variety of species including the Amazon river dolphin (Boto), piranhas, electric eels, and more than 2,500 fish species.
• The Amazon rainforest, nourished by the river, houses around 10% of all known species, playing a crucial role in global biodiversity.

Source: NewYork Times

 Syllabus

• Prelims & Mains – SCIENCE & TECHNOLOGY

Context: On October 8, John Hopfield and Geoffrey Hinton won the 2024 Nobel Prize for physics for foundational discoveries and inventions that enable machine learning with artificial neural networks.

Background: –

• Their work lies at the roots of a large tree of work, the newest branches of which we see today as artificially intelligent (AI) apps like ChatGPT.

What are Artificial Neural Networks (ANNs)?

• Artificial Neural Networks (ANNs) are computational models inspired by the human brain’s neural networks. They are composed of layers of interconnected artificial neurons that process data in a way that mimics human learning. ANNs are the foundation for many AI applications, particularly those involving pattern recognition, data analysis, and decision-making.

Structure of ANNs

• Neurons and Layers: ANNs consist of interconnected units called neurons, organized into layers. There are typically three types of layers:
  • Input Layer: Receives the initial data.
  • Hidden Layers: Perform computations and feature extraction.
  • Output Layer: Produces the final result or prediction.

Types of ANNs

• Feedforward Neural Networks (FNNs): The simplest type, where connections do not form cycles. Data moves in one direction from input to output.
• Convolutional Neural Networks (CNNs): Specialized for processing grid-like data such as images. They use convolutional layers to automatically and adaptively learn spatial hierarchies of features.
• Recurrent Neural Networks (RNNs): Designed for sequential data, such as time series or natural language. They have connections that form cycles, allowing them to maintain a memory of previous inputs.
• Autoencoders: Used for unsupervised learning, these networks aim to learn a compressed representation of the input data.

Applications of ANNs

• Image and Speech Recognition: CNNs are widely used for tasks like identifying objects in images and recognizing spoken words.
• Natural Language Processing (NLP): RNNs and their variants, such as LSTM (Long Short-Term Memory) networks, are used for language translation, sentiment analysis, and more.
• Healthcare: ANNs assist in diagnosing diseases, predicting patient outcomes, and personalizing treatment plans.
• Finance: Used for stock market prediction, fraud detection, and risk management

Source: The Hindu

 Syllabus

• Prelims & Mains – SCIENCE & TECHNOLOGY

Context: The Major Atmospheric Cherenkov Experiment (MACE) Observatory was inaugurated on October 4, 2024, in Hanle, Ladakh.

Background:

• MACE Observatory is a monumental achievement for India, and it places our nation at the forefront of cosmic-ray research globally.

About MACE OBSERVATORY

• Located at Hanle, Ladakh, at an altitude of approximately 4,300 meters, making it the highest imaging Cherenkov telescope in the world.
• Significance: It is the largest imaging Cherenkov telescope in Asia.
• Built By: Bhabha Atomic Research Centre (BARC) with support from the Electronics Corporation of India Ltd (ECIL) and other Indian industry partners.

Purpose and Functionality

• The MACE Observatory is designed to study high-energy gamma rays. Gamma rays do not reach the Earth’s surface but interact with the atmosphere to create high-energy particles that emit Cherenkov radiation. The telescope captures these flashes to trace them back to their cosmic sources.

Scientific and Socio-Economic Impact

• Research: The telescope will advance cosmic-ray research, allowing scientists to study phenomena such as supernovae, black holes, and gamma-ray bursts.
• Community Engagement: The project also aims to support the socio-economic development of Ladakh, encouraging local students to pursue careers in science and technology.

Unique Advantages

• Location Benefits: Hanle offers extremely low light pollution, which is ideal for gamma-ray observations. Its longitudinal position allows MACE to observe sources that are not visible from other parts of the world.

About Cherenkov radiation

• Cherenkov radiation is a fascinating phenomenon that occurs when a charged particle, such as an electron, travels through a dielectric medium (like water or glass) at a speed greater than the phase velocity of light in that medium.

Physical Origin

• Speed of Light in Medium: While the speed of light in a vacuum is a universal constant (approximately (3 \times 10^8) meters per second), it slows down when it passes through a medium like water or glass. For instance, light travels at about 75% of its speed in a vacuum when in water.
• Charged Particles: When charged particles (e.g., electrons) move faster than the speed of light in that medium, they emit Cherenkov radiation.

Mechanism

• Electromagnetic Shockwave: This radiation is analogous to a sonic boom, which occurs when an object exceeds the speed of sound in air. Similarly, Cherenkov radiation is an electromagnetic shockwave produced when a particle exceeds the speed of light in a medium.

Appearance

• Blue Glow: Cherenkov radiation typically appears as a faint blue glow. This is because the emitted photons are in the blue and ultraviolet part of the electromagnetic spectrum.

Historical Context

• Discovery: The phenomenon was first observed by Soviet physicist Pavel Cherenkov in 1934. He noticed a faint blue light around a radioactive preparation in water.
• Nobel Prize: Pavel Cherenkov, along with Ilya Frank and Igor Tamm, received the Nobel Prize in Physics in 1958 for their theoretical explanation of this effect.

Applications

• Nuclear Reactors: Cherenkov radiation is commonly observed in the water surrounding nuclear reactors, where it serves as a visual indicator of high-energy particles being emitted.
• Particle Detectors: Cherenkov detectors are used in particle physics to identify high-speed charged particles. These detectors are crucial in experiments involving cosmic rays and high-energy physics.
• Medical Imaging: Recent advancements have explored the use of Cherenkov radiation in medical imaging, particularly in radiotherapy, where it helps visualize the distribution of radiation doses.

Source: PIB

 Syllabus

• Prelims – ENVIRONMENT

Context: In a significant breakthrough for conservation efforts, a newly colonised habitat of Nilgiri Tahr has been discovered in Pasumalai.

Background: –

• Surrounded by shola forests and abandoned coffee estates, the area has potential grassland cover atop hillocks and cliffs, providing the Tahr with necessary escape terrains – critical for their survival.

About Nilgiri tahr 

• The Nilgiri tahr (Nilgiritragus hylocrius) is a unique species of mountain ungulate endemic to the Nilgiri Hills and the southern portion of the Western and Eastern Ghats in the states of Tamil Nadu and Kerala in southern India.

Physical Description

• Appearance: Nilgiri tahrs are stocky goats with short, coarse fur and a bristly mane. Males are larger and darker than females, with both sexes having curved horns.
• They develop a light grey area on their backs, earning them the nickname “saddlebacks”.

Habitat and Distribution

• Location: The Nilgiri tahr inhabits the open montane grassland habitats of the South Western Ghats montane rain forests ecoregion, at elevations ranging from 1,200 to 2,600 meters .

Range:

• The Nilgiri tahr can be found only in India.
• Historically, they were found along the entire stretch of the Western Ghats, but now they are confined to small fragmented pockets.
• Currently, the Nilgiri tahr distribution is along a narrow stretch of 400 km in the Western Ghats between Nilgiris in the north and Kanyakumari hills in the south of the region.
• Though there are smaller populations found in the Palani hills, Srivilliputtur, and the Meghamalai and Agasthiyar ranges, only two well-protected, large populations are documented — one from the Nilgiris and the other from the Anamalais, including the high ranges of Kerala.
• The Eravikulam National Park in Anamalai hills, Kerala, is home to the largest population of the Nilgiri tahr, with more than 700 individuals.
• Diet: Nilgiri tahrs are primarily grazers, feeding on a variety of grasses, herbs, and shrubs.
• Behavior: They are well-adapted to their rugged, mountainous habitat, with cloven hooves that help them climb rocks and steep slopes.

Conservation Status

• Threats: The Nilgiri tahr faces several threats, including habitat loss due to deforestation, competition with domestic livestock, hydroelectric projects, and monoculture plantations. Occasional hunting for their meat and skin also poses a threat.
• Species is listed as Endangered in the IUCN Red List of Threatened Species and is protected under Schedule I of the Wildlife (Protection) Act of India, 1972.
• The Nilgiri tahr is the only mountain ungulate in southern India amongst the 12 species present in India. It is also the state animal of Tamil Nadu.

Source: New Indian Express

Q1.) Consider the following statements regarding the Nilgiri tahr:

1. The Nilgiri tahr is the only mountain ungulate found in southern India.
2. The largest population of the Nilgiri tahr is found in the Eravikulam National Park in Kerala.
3. The species is listed as Critically Endangered on the IUCN Red List.
4. The Nilgiri tahr is protected under Schedule I of the Wildlife (Protection) Act of India, 1972.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 2, 3, and 4 only
(c) 1, 2, and 4 only
(d) 1 and 4 only

Q2.) With reference to the Major Atmospheric Cherenkov Experiment (MACE) Telescope, which of the following statements is/are correct?

1. It is located at Hanle in Ladakh and is the largest imaging Cherenkov telescope in Asia.
2. The telescope is designed to study high-energy gamma rays that directly reach the Earth’s surface in large amounts.
3. MACE Telescope was built by the Bhabha Atomic Research Centre (BARC) in collaboration with other Indian industry partners.

Select the correct answer using the codes given below:

(a) 1 only

(b) 1 and 3 only

(c) 2 and 3 only

(d) 1, 2, and 3

Q3.) The Amazon River, located in South America, is one of the most significant river systems in the world. Consider the following statements about the Amazon River:

1. The Amazon River is the longest river in the world.
2. It accounts for about 20% of the world’s fresh river water discharge.
3. The Amazon Basin covers more than 70% of South America’s landmass.
4. The Amazon River is primarily fed by major tributaries, including the Rio Negro, Madeira, and Tapajó

Which of the above statements are correct?
a) 1 and 3 only
b) 2 and 4 only
c) 1, 2, and 4 only
d) 2, 3, and 4 only

Comment the answers to the above questions in the comment section below!!

ANSWERS FOR ’  9th October 2024 – Daily Practice MCQs’ will be updated along with tomorrow’s Daily Current Affairs

Q.1) –  c

Q.2) – a

Q.3) – c