Environment & Ecology
- 04 cr hit by arsenic contamination in Bengal
- Tamil Nadu in the cycle of drought and floods
Art & Culture
- Reviving Assam’s ancient ink
- Move to get world heritage status for Sankaram
Science & Technology
- Telescope upgrade to sniff out solar storms
- Scientists discover five new sub-atomic particles
- New Wi-Fi system to offer super-fast connectivity
Key Facts for Prelims
- India’s longest road tunnel
- First fully India-made train Medha flagged off
Environment & Ecology
1.04 cr hit by arsenic contamination in Bengal
According to recent report tabled in the Lok Sabha, West Bengal has the highest number of arsenic-affected people in the country.
- The total number of arsenic-affected people in the country is about 1.48 crore (as of March 2017).
- West Bengal has topped the list with more than 1.04 crore arsenic-affected persons.
- Bihar is second with 16.88 lakh persons, with Assam is third with 14.48 lakh victims.
- West Bengal’s 83 blocks in eight districts have ground water affected by arsenic contamination.
- Despite the West Bengal State government’s efforts to curb the Arsenic menace, there is still a lot to be done. So far, state government was able to provide safe drinking water to 52% of the arsenic-affected areas in Bengal.
According to the WHO’s guidelines for drinking water quality (2011), the permissible limit of Arsenic in groundwater is .01 m/ litre. However, in India the permissible limit in drinking water was only recently been revised from .05 mg/litre to .01 mg/litre.
West Bengal government recently had initiated a project to provide safe drinking water to more than six lakh people in the arsenic-affected blocks. However, there is slow progress in setting up water treatment plants since the technology for removal of arsenic is new and expensive.
Arsenic in groundwater:
- Arsenic in ground water is a geogenic contaminant i.e. caused by natural geologic processes.
- Arsenic-containing groundwater in Ganga River basin is hosted by the sediments deposited by the rivers during the late Quaternary or Holocene age (<12 thousand years).
- Incidence of high arsenic in groundwater reported from various parts of the country, particularly in the Ganga- plains is a serious threat to the health of human being.
- Arsenic occurrences in ground water in these areas is highly sporadic in nature and all the sources in these areas are not necessarily contaminated.
Over the last three decades numerous measures have been initiated which includes alternate arrangement for supply of arsenic free water to the affected populace and providing arsenic removal plants.
Technological options to combat arsenic menace:
In groundwater, to ensure supply of arsenic free water, in the affected areas, following technological options are available to combat arsenic menace:
- In-situ remediation of arsenic from aquifer system,
- Ex-situ remediation of arsenic from tapped groundwater by arsenic removal technologies,
- Use of surface water source as an alternative to the contaminated groundwater source,
- Tapping alternate safe aquifers for supply of arsenic free groundwater or combination of above techniques.
Tamil Nadu in the cycle of drought and floods
Tamil Nadu is emerging as a State of climate paradoxes with its volatile weather patterns.
- It’s a bitter irony for the State that witnessed unprecedented floods in its north coastal districts in 2015 that pushed its north-east monsoon rainfall to an excess of 52% to now be in the grip of a severe drought.
- The devastating blow to agriculture and water resources came with 2016 turning out to be one of the driest years.
Reasons for this drought:
The State was hit by the worst annual rainfall in 140 years as it received just 543 mm of rain against the yearly average of 920 mm. This is the lowest recorded after 1876 when Tamil Nadu registered 534 mm, leaving a shortfall of 42%.
- A weak La Nina over the equatorial Pacific that followed a year of strong El Nino is cited as one of the reasons for the drought.
- Mismanagement of surface water resources, over-exploitation of groundwater to compensate for the loss of resources in dry waterbodies and the lack of timely policies have pushed the State into a drought.
- Meteorology experts note that the south-west monsoon rainfall often complements or compensates the State’s rainfall during the north-east monsoon, which accounts for a major share of the yearly rainfall, though it may not have the same impact as in the neighbouring States. Last year was particularly bad for farmers across all districts as both monsoons failed to bring sufficient rain.
- Population density in many regions of Tamil Nadu, which is higher than other drier regions like Rayalaseema in Andhra Pradesh, also influences the impact of drought.
- The lack of water resources for crops is feared to lead to a shortfall in paddy cultivation, influx from other States and a hike in the prices of essential commodities.
- Experts have raised concerns over the failure to obtain target crop yields, including tree crops, owing to soaring temperatures.
- Drought has dealt farmers a double blow as the paddy crop failure will increase the fodder crisis, hitting livestock production.
- Several parts of the State are already experiencing acute drinking water shortage. Given the climate variability in which rainfall intensity is set to be higher and distribution will be limited to a few days.
- The State government must chalk out plans to augment the storage capacity of waterbodies and protect waterways and encourage farmers to adopt crop diversification, create farm ponds and use fewer water-intensive crops.
- Unless the State government draws up a long-term strategy to manage its resources, prioritise agrarian needs and come up with better crop insurance policies, Tamil Nadu will not be able to break the vicious cycle of droughts and floods.
Art & Culture
Reviving Assam’s ancient ink
By unravelling the science behind Assam’s ancient herbal ink ‘mahi’, researchers are planning to recreate the lost techniques of manuscript writing. They say their efforts could boost heritage tourism.
All about ‘mahi’ ink:
- The technique involves extracting ‘mahi’ using cow urine from a cocktail of fruit pulp and tree bark such as haritaki, amla, bibhitakhi or bhomora, mango and jamun — often infused with the blood of eels or catfish. Rust from iron tools or nails was added for an intense black hue.
- One of the reasons for the manuscripts’ stability is the anti-fungal activity of the ink. This is due to its raw materials, including astringent fruits and cow urine, which seems to have a protective effect on cellulosic sancipat against fungal attack in the hot and humid climate of Assam.
- In contrast, some formulations of acidic iron gall ink — which was in use at the same time in Europe — can render documents illegible by causing loss of text, bleeding and fading due to ink corrosion.
- The major phytochemical constituents in ‘mahi’ have been identified as phenolic acids, flavonoids and tannins and their complexes with iron.
- Though there are several recorded recipes for ‘mahi’ formulation, one commonality exists for all: the season during which it is concocted.
- It is only prepared (in natural settings) in the winter season. The low temperature and dry conditions in winter ensure minimum exposure of the mixture to microbes and heat, which may decompose the dyes during the long time needed for extraction.
- Another interesting feature is that the pH of mahi remains neutral because of cow urine and the absence of acidic ingredients like vinegar. No stabiliser is used in mahi.
- ‘Mahi’ was used in early and medieval Assam for writing on ‘sancipat’ (folios made of the bark of the sanci tree) manuscripts.
- Some folios were gifted by Kumar Bhaskar Barman, the then King of Pragjyotishpura (ancient Assam) to Harshavardhana, an emperor who ruled north India from 606 to 647 C.E., a testimony to the period of use.
Move to get world heritage status for Sankaram
The Buddhist Heritage sites at Salihundam (Srikakulam district) and Sankaram near Anakapalle in Visakhapatnam district, in addition to Lepakshi (Anantapur district) and the Nagarjunakonda International Museum (Guntur district) are likely to find a place in the list of UNESCO World Heritage Sites.
- In this regard, the Archaeological Survey of India (ASI) has sought a proposal from its Hyderabad unit, for sending it to the Unesco World Heritage Centre for tentative listing.
Key facts about Sankaram:
- Sankaram, also known as Bojjannakonda, was excavated under the aegis of Alexander Rim in 1906.
- A gold coin belonging to the Samudragupta period, copper coins of the Chalukya king, Kubja Vishnu Vardhan, coins of Andhra Satavahanas and pottery were discovered at the site.
- An interesting aspect of the Bojjannakonda finds is that they feature all the three phases of Buddhism: Hinayana, Mahayana and Vajrayana.
- A stairway leads to a large double-storeyed cave on a hill. The rectangular cave has a doorway and is flanked by ‘dwarapalakas’ on either side.
- There is a rock-cut stupa, standing on a square platform, at the centre of the cave. A series of rock-cut caves and monolithic structures standing on rock platforms are seen on the northern side of the hill.
- The upper cave has a rectangular doorway, flanked by figures of the Buddha on either side.
- The imposing figures of the Buddha in a seated meditative posture and the stupa are the main attractions for tourists at Bojjannakonda.
- To the west of Bojjannakonda is another hillock, Lingalakonda or Lingalametta, where a number of monolithic and structural stupas can be seen.
- The caves at Bojjannakonda and those in Takshasila are similar. The word ‘Sangrama’ was in use at Takshasila but was never used in Andhra Pradesh. These two features suggest that Bojjannakonda was influenced by Buddhist practices in northern India.
Science & Technology
Telescope upgrade to sniff out solar storms
The GRAPES-3 experiment at Tata Institute of Fundamental Research’s (TIFR) Cosmic Ray Laboratory in Ootacamund in Tamil Nadu is getting upgraded.
- The telescope made news last year when it detected the effect of a solar storm that hit the earth in June 2015.
- GRAPES-3 has an important role in understanding the propagation of storms from the L1 point to its impact on the Earth.
About GRAPES 3:
- The GRAPES-3 experiment (or Gamma Ray Astronomy PeV EnergieS phase-3) located at Ooty in India started as a collaboration of the Indian Tata Institute of Fundamental Research and the Japanese Osaka City University, and now also includes the Japanese Nagoya Women’s University.
- GRAPES-3 is designed to study cosmic rays with an array of air shower detectors and a large area muon detector.
- It aims to probe acceleration of cosmic rays in the following four astrophysical settings. These include acceleration of particles to,
- ~100 MeV in atmospheric electric fields through muons,
- ~10 GeV in the Solar System through muons,
- ~1 PeV in our galaxy,
- ~100 EeV in the nearby universe through measurement of diffuse gamma ray flux.
- The sun is at a distance of 150 million kilometres from the earth, and satellites have been placed at a distance of nearly 1.5 million kilometres, at the so-called L1 point, where they orbit the Sun along with the Earth.
- Since charged particles from a solar storm will first impact the satellites before hitting the earth, they act as an early warning system. Depending on the speed of the storm, it will take about 20-40 minutes to reach the earth from the L1 point.
- The observations began with 217 plastic scintillators and a 560 m2 area muon detector in 2000. The scintillators detect charged particles contained in extensive air showers produced by interaction of high energy cosmic rays in the atmosphere.
Significance of the latest upgrade:
- The upgrade will play a major role in getting precise information about the propagation of storms in ‘the last million miles’ (from the L-1 point) of their journey from the Sun to the earth.
- The upgraded detector will have an increased coverage of the sky and improved capacity to determine the direction of incident cosmic rays.
- The latter property, of being able to discern the direction of detected particles, makes it unique among cosmic ray detectors in the world; it can also to measure the intensity of the particles.
- Since the enhanced facility can cover a wider field of view (from present 37% to 57%), the chances of spotting solar storms will be higher.
Need to understand solar storms:
- It is important to know the time when plasma will reach the earth, accurately, so that preventive and protective measures can be put into place in case a solar storm were to strike the earth.
- If the earth’s magnetic field were to be weakened by extreme solar storms, charged particles would shower on to the planet. Apart from rendering electronic devices defunct, charged particles in an extreme solar storm can also short current carrying over-head high voltage lines, leading to large-scale transformers burn out and thereby, power blackouts.
- A 2008 study conducted by the U.S. National Academy of Sciences estimated that an extreme event could lead to a loss of 40% of transformers in the U.S., which, in turn, could take years to restore.
- The up side is that the way to prevent such a disaster is well understood: simply switch off the power lines on being informed of an approaching solar storm! And for this to be possible, an accurate determination of the time taken for the solar storm to travel to the earth is needed, which is where the GRAPES-3 set up comes in.
[Ref: The Hindu]
Scientists discover five new sub-atomic particles
Scientists using the world’s largest and most powerful particle accelerator Large Hadron Collider accelerator (LHC) at CERN (European Organisation for Nuclear Research) have discovered a new system of five particles all in a single analysis.
- The uniqueness of this discovery is that observing five new states all at once is very rare.
- According to the standard convention, these particle states were named Oc(3000)0, Oc(3050)0, Oc(3066)0, Oc(3090)0 b Oc(3119)0.
- The new particles were found to be in excited states (a particle state that has a higher energy than the ground state or absolute minimum configuration) of a particle called Omega-c-zero.
- Omega-c-zero is a baryon. It is a particle with three quarks, containing two strange and one charm quark.
- LHCb collaboration by analysing trajectories and energy left in the detector by all the particles in this final configuration were able to trace back the initial event he decay of the Omega-c-zeroand its excited states.
- Now quantum numbers of these new particles, characteristic numbers used to identify the properties of a specific particle and their theoretical significance will be determined.
Significance of the discovery:
- It will contribute to understanding how the three constituent quarks are bound inside a baryon.
- It will also help to probe the correlation between quarks, which plays a key role in describing multi-quark states, such as tetraquarks and pentaquarks.
What is baryon?
- Baryon is a composite subatomic particle made up of three quarks (a triquark, as distinct from mesons, which are composed of one quark and one antiquark).
- Baryons and mesons belong to the hadron family of particles, which are the quark-based particles.
- The most familiar baryons are the protons and neutrons that make up most of the mass of the visible matter in the universe.
About Large Hadron Collider:
The Large Hadron Collider (LHC) is the world’s largest and most powerful particle collider, most complex experimental facility ever built, and the largest single machine in the world.
- It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and engineers from over 100 countries, as well as hundreds of universities and laboratories.
- The LHC is based at the European particle physics laboratory CERN, near Geneva in Switzerland.
- The aim of the LHC is to allow physicists to test the predictions of different theories of particle physics, including measuring the properties of the Higgs boson and searching for the large family of new particles predicted by supersymmetric theories, as well as other unsolved questions of physics.
- The collider has four crossing points, around which are positioned seven detectors, each designed for certain kinds of research.
- The LHC’s computing grid is a world record holder.
New Wi-Fi system to offer super-fast connectivity
Scientists from Eindhoven University of Technology in Netherlands have developed a new wireless Internet network based on infrared rays that is reportedly 100 times faster than existing Wi-Fi (Wireless Fidelity) networks.
- It has a huge capacity, more than 40 Gigabits per second (Gbit/s). It also does away with the need of sharing Wi-Fi, as every device gets its own ray of light.
- A light-based system, also known as ‘Li-Fi,’ could make wireless networks much more secure.
- The wireless data in this network comes from a few central ‘light antennas’, that are able to precisely direct the rays of light supplied by an optical fibre.
- These antennas contain a pair of gratings that radiate light rays of different wavelengths at different angles (passive diffraction gratings).
- If a user is walking and his smartphone or tablet is moving out of the light antenna’s direction, then another light antenna takes over.
- In this system, changing the light wavelengths also changes the direction of the ray of light. It uses safe infrared wavelength that does not reach the retina in the eye.
- The network tracks the precise location of every wireless device using its radio signal transmitted in the return direction.
- Different devices are assigned different wavelengths by the same light antenna and so do not have to share capacity.
- It uses infrared light with wavelengths of 1,500 nanometres and higher. Current, Wi-Fi uses radio signals with a frequency of 2.5 or five gigahertz.
- On this network, researchers have managed to achieve a speed of 42.8 Gbit/s over a distance of 2.5 metres. It is hundred times fast than best Wi-Fi systems currently available that can provide users maximum 300 mbps speed.
- The new system so far has used the light rays only to download. Uploads are still done using radio signals since in most applications much less capacity is needed for uploading.
Key Facts for Prelims
India’s longest road tunnel
- India’s longest surface tunnel in Jammu and Kashmir’s Udhampur district is complete.
- It will be open to traffic soon, following successful completion of trial runs for peak and off-peak hours.
- It has taken nearly six years for the project’s completion, since the work started in May 2011 in the lower Himalayan mountain range.
- The 9-km-long twin-tube tunnel at Chenani passes through the lower Himalayan mountain range on Jammu- Srinagar National Highway.
- It is India’s first tunnel equipped with world class integrated tunnel control system through which ventilation, signals, fire control, communication and electrical systems are automatically actuated.
- It reduces travel distance between Jammu and Srinagar by 30 kilometres and save time by three to four hours. The road distance from Chenani and Nashri will now be 10.9 km, instead of present 41 km.
- The tunnel will provide all-weather road connectivity to the Valley and avoid landslide-prone stretch. It will help to boost the trade and commerce and tourism in the valley.
- This engineering marvel is being called the ‘Tunnel of Hope’ in Kashmir.
First fully India-made train Medha flagged off
- First fully India-made train (rake) Medha was flagged off at Dadar station in Mumbai.
- The effort aims to boost rail connectivity in the region and enhance the convenience of the people.
- Two Medha trains were on a trial since the last two years. Both the trains have been designed and built at the Integral Coach Factory in Chennai. They will be running on the Western Railway network.
- It is powered by a Hyderabad-based firm Medha Servo Drives.
- The company has installed LED lighting inside the train, which will help save energy by almost 30-35% in comparison to the existing trains.
- The train also has a special indigenous 3 phase propulsion system unlike the earlier electric multiple units of the Indian railways, which have systems from either Bombardier or Siemens.
- The in-built system will help minimise breakdowns during the travel.