[Science-Tech] TheHindu (March2May) (Part 1 of 3): Agriculture, Environment-Biodiversity, Silage, Salt Pump, Sagar Nidhi, El Nino Modoki & more

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Pavan Kumar
  1. Prologue
  2. Agriculture
    1. Caffeine
    2. NAA, IAA Plant hormones
    3. Potash fertilizer
    4. e-Velanmai
    5. Citrus greening
    6. Membrane transporters
    7. Silage
    8. Farm Ponds
    9. High density multi species cropping system
    10. SRI Rice cultivation
    11. High Density Planting (HDP)
    12. Ornamental fish farming
  3. Environment and Biodiversity (EnB)
    1. Climate / Geography related
      1. Salt Pump
      2. El Nino Modoki
      3. Monsoon: Tibetan Plateu and ENSO
    2. Ocean Related
      1. Sagar Nidhi
      2. Dynamic positioning system (DPS)
      3. Polymetallic nodules
    3. Pollution related
      1. Gold Extraction without pollution
      2. Nanotech pollution detectors
      3. Atom Bicycle generator (USB)
    4. Citizen science projects
      1. common bird monitoring of India programme
      2. People’s biodiversity register
    5. Flora and Fauna
      1. Insects’ circulatory system
      2. Why baby leaves are red?
      3. Toe control
      4. Why do ants like sugar?

Prologue

  • This three part article series contains the Sci-tech related topics appeared in The Hindu Thursday edition in March, April, May of 2013. (earlier months already covered and available under Mrunal.org/snt)
  • Just because UPSC did not ask much current affairs in prelims 2013, you should not become complacent/lazy in your preparation of current affairs.
  • Reason: even prelim 2012 did not have that much current affairs (compared to earlier years) but still GS mains 2012 was jam packed with questions based on current affairs. (Analysis of Mains 2012 given here click me)
  • so how and where does Hindu Science Tech help? consider the following topics on official syllabus of UPSC
MainsSubtopicSyllabus topics (non exhaustive)Example topics covered in the three articles
GS paper 1Geography
  1. Distribution of key natural resources across the world (including South Asia and the Indian sub-continent);
  2. Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.
  3. geographical features and their location- changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.
  1. Mining of Polymetallic nodules from oceans
  2. El Nino Modoki
GS paper 3AgroMajor crops cropping patterns in various parts of the country ……e-technology in the aid of farmers
  1. ornamental fish farming
  2. e-Velanmai project
  3. High Density Planting
Sci-TechScience and Technology- developments and their applications and effects in everyday lifeglass fibre reinforced gypsum panels etc.
Achievements of Indians in science & technology; indigenization of technology and developing new technology.3Nethra, cholangioscope
Awareness in the fields of IT, Space, Computers, robotics, nano-technology, bio-technology and issues relating to intellectual property rights.BRCA genes patenting, GSLV mk3 etc.
Conservation, environmental pollution and degradation, environmental impact assessmentAmmonia detectors, gold extraction using nano-particles.

^this is just an example, syllabus contains lot of topics, where you’ll find utility of sci-tech and allied topics (and other news items). Therefore, I suggest you read the syllabus topics itself for multiple times- so the name of each topic gets permanently imprinted in your brain and later whenever you read a news-item you can see its application in a particular GS paper. Read the UPSC notification, page 13 onwards for the official syllabus:Click Me

Notes:

  1. Just because I’m providing compilation for March-April-May, doesn’t mean “the end” of topics happened in that time-frame. You should do ‘follow-up’ on your own, reading / researching the topics from other sources. Because nothing prevents UPSC from asking anything that is not provided/explained here.
  2. I’ve covered only Thursday edition. However newspaper covers Science tech and allied news topics even in the Non-Thursday editions. And again, nothing prevents UPSC from asking anything from there. So one should keep habit of maintaining daily notes from the newspaper on his own.
  3. In short, I’m just a supplement and catalyst for the preparation- not a substitute of TheHindu, Indianexpress, Yojana, Kurukshetra and other standard reference sources. And same applies for any other website and coaching. UPSC Success requires lot of self-study on your own.

Anyways, let’s start the three part article series:

  • part 1 of 3= Agro and Enb
  • part 2 of 3 = healthcare related
  • part 3 of 3 = space-research, electronics and mock questions

Agriculture

Caffeine

How was Coffee and Tea introduced in India?

Coffee

Tea

  • as per the legend, in late 16th century Haji Baba Budan smuggled coffee beans from Yemen.
  • And planted them on the Chikamagalur hills in Karnataka.
  • Then coffee plantations started and coffee became popular in South India.
  • Was introduced later than coffee.
  • In early 19th Century, the colonial British who copied it from the Chinese and planted it in Assam and Darjeeling.
  • Thus Tea become popular in the northern India.
  • Both tea and coffee have caffeine.
  • but only tea contains both caffeine and tannin.
  • But why do these plants go to the trouble of making the molecule in the first place? two reasons

#1: determine herbivores

  • Because of Caffeine, the raw coffee bean or tea-leaf is bitter to taste, hence animals won’t eat it, plant can grow and flourish.

#2: attract bees

  • While plant-derived drugs like caffeine (tea, coffee) and nicotine (tobacco) are lethal in high doses, they do generate pleasant effects when taken in very low doses.
  • Caffeine is also found in the nectar of flowers of those plants.
  • The caffeine in nectar of flower= gets the bees addicted hence they keep coming back and help in pollination.

NAA, IAA Plant hormones

  • Naphthyl acetic acid (NAA) and Indole acetic acid (IAA) are synthetic hormones
  • NAA is cheaper as compared to IAA.
  • they are commonly used for improving rooting in mulberry cuttings.
  • Mulberry is commercially cultivated for its foliage to feed silkworms.

Potash fertilizer

  • Potash is one of the major nutrients required by all crops.
  • India’s entire requirement of potassic fertilizer is met by imports and distributed to farmers at subsidised price.
  • Problem= increases trade deficit, weakens rupee+ adds subsidy burden.
  • Indian soils are naturally rich in potassium and now scientists have identified a potash mobilizing bacterium to mobilize this native potassium for plant absorption.
  • Field testing going on for paddy, groundnut and vegetable crops.
  • If Potash Mobilizing Bacterial (KMB) biofertilizer and biopesticides are used, farmers can save upto 50 per cent of their potassium fertilizer requirement.

e-Velanmai

  • Velanmai is a Tamil word meaning agriculture.
  • it is an IT project for dissemination of agricultural information Tamil Nadu Agricultural University (TNAU) directly to farmers on a pilot basis in selected areas of the State.
  • Prior to the introduction of e-Velanmai project, many farmers stated that they had to depend on the shop keepers/dealers in their area for information.
  • But now they are able to access all information related to agriculture at their farm gate itself.

Citrus greening

  • disease of citrus which greatly affects the production of the fruits in several parts of India.
  • Infected fruits are small, lopsided with bitter taste.
  • Such fruits may fall prematurely; while those that remain on the tree do not colour properly, remaining green on the shaded side.

Membrane transporters

  • they’re a class of plant proteins.
  • The transporter genes in the plant’s seeds. These genes are usually expressed in the root so that the plant could take in nutrients from the soil.
  • Now scientists are conducting research on these genes responsible for transport, so they could improve the efficiency with which plants take up and use water and nutrients.

benefits?

  1. greenhouse-grown rice with three- to four-fold higher levels of iron in polished grain.
  2. In a similar fashion, zinc content of cereal grains could be increased
  3. The amount of phosphate and nitrate fertilisers used for cultivation could then be substantially reduced.
  4. drought tolerance in plants as well as their ability to grow in other adverse conditions, such as in saline or acidic soils.

Silage

  • Silage is fermented, high-moisture stored fodder.
  • It can be fed to cud chewing animals such as cattle, sheep and goats.
  • It is fermented and stored in a process called ensilage, ensiling or silaging
  • Usually made from grass, maize, sorghum or other cereals using the entire green plant (not the grain alone).

Silage Advantages?

  • During summer (or when monsoon fails) the green fodder becomes unavail.
  • Hence Prolonged preservation of fodder in the form of silage becomes the key to overcome the increasing constraints in green fodder availability.

Traditional methods for Silage production

  • Dig a pit in the soil
  • Place the harvested matter inside and covering it with soil.

Problem in traditional method?

  1. Landless farmers cannot go for such pit methods.
  2. This method makes it difficult to transport the silage from the pit to the cattle shed
  3. Labor intensive and costly.

Farm Ponds

  • The farm ponds are constructed at the lower side of the fields and the runoff from the higher side of the fields are channelized into the pond.
  • provides Fodder and drinking water.
  • Some farmers have also started cultivating wheat and chickpea using the pond water successfully.

High density multi species cropping system

  • is one of the mixed cropping systems
  • Here, a number of compatible crops are grown in an area to meet the diverse needs of the farmers such as food, fuel, timber, fodder and cash.

other benefits?

  1. control of weeds,
  2. soil and water conservation,
  3. regulated temperature and favourable microbial activity in the soil.
  4. generation of recyclable biomass for organic manure.

SRI Rice cultivation

  • SRI=systematic rice intensification method
  • It is the universally accepted as a proven method to increase rice yield.

principles of SRI cultivation

  1. transplant seedlings when they’re young
  2. plant seedlings in 25×25 or wider spacing, to reduce competition for sunlight and nutrients.
  3. Reduce external inputs (water, fertilizer, pesticides)
  4. Prevent soil from becoming anoxic (without oxygen). For this, use mechanical weeder regularly.
  5. Add in-situ/ex-situ organic matter as much as possible, to increase the soil organic matter.
  6. Use green manure, bio fertilizer, compost.

High Density Planting (HDP)

  • It is an advance technique of fruit plantation.
  • Through HDP technique, 4,000 to 5,000 plants can be planted in a hectare and the yield improves radically.
  • This technique is more useful for perennial crops because it allows efficient use of land and resources,
  • In India, HDP technology has been successfully used in banana, pineapple, papaya and mango, guava and citrus where the yield has increased two to three times.
  • also helps in farm mechanization, weed controls.

Ornamental fish farming

  • Ornamental fishes are kept in aquarium at home and in offices.
  • Examples of ornamental fishes: guppies, mollies, sword tails, angelfishes, goldfishes.
  • The global business of Ornamental fish rearing, accessories (tanks, lights, water pipes etc.) and fish feed =is worth ~$14 Billion
  • In India we have hundreds of exotic and indigenous ornamental fish varieties but unfortunately, India’s share in international trade of ornamental fish = <1 %.
  • The earning potential of this sector neither understood nor exploited in a technology driven manner. otherwise we can give tough competition to the major exporters such as Singapore, Malaysia etc. (USA is the largest importer).

potential benefits of ornamental fishing

  1. substantial employment opportunities,
  2. side income for the farmer,
  3. earning foreign exchange.

Government’s action:

  1. NABARD provides finance via Commercial banks, RRB etc.
  2. Marine Products Export Development Authority (MPEDA) under Ministry of Commerce and industry provides subsidy

Environment and Biodiversity (EnB)

Climate / Geography related

Salt Pump

  • salinity of the oceans that surround India play an important part in the complex interactions between atmosphere and sea
  • and thus indirectly determines climate over the subcontinent.
Arabian SeaBay of Bengal
  • got little rain, except off the west coast of India
  • Given the evaporation that took place, its salt levels would increase.
  • rivers, like the Ganges bring plenty of fresh water,
  • + the Bay of Bengal itself receives lot of rain during monsoon.
  • This excess fresh water would reduce its salinity.
Result: it is more salty than Bay of Bengal.It is less salty than Arabian sea.

What is Salt pump?

  • so far we saw that Arabian sea is more salty than Bay of Bengal.
  • Summer Monsoon Current, flowing eastward, takes salty water from the Arabian Sea to the Bay. and thus helps them to help maintain salinity levels.
  • But this saltier water, however, slides under the lighter surface water of the Bay.
  • Hence Maintaining the salt balance of the Bay therefore demands upward mixing of this saltier, subsurface water.
  • Based on 2009 ocean cruise data, scientists found that this saltier water erupted upward intermittently from its sub-surface abode to mix with the fresher surface water. they call it “Salt pump”.
  • mechanism driving this ‘salt pump’ was not clear at present

El Nino Modoki

  • during pre-monsoon and post-monsoon seasons in the North Indian Ocean, more cyclones form in the Bay of Bengal than in the Arabian Sea
  • Scientists have now discovered why in some years more cyclones form in the Arabian Sea than usual.
  • This is due to a newly discovered Phenomenon (2007) El Nino Modoki
El NinoEl Nino Modoki
  • suppresses cyclone formation in the Arabian Sea.
It creates more cyclones in the Arabian sea.

How El Nino Works

How does El Nino Modoki work?

It Causes warm moist conditions in the Central Pacific and dry cold conditions in Eastern and western pacific.

Divergence

  • Divergence (opposite of convergence) means surface winds move away from each other and result in low relative vorticity (rotational flow of winds)
  • These conditions are not conducive for cyclones.
  • El Nino Modoki creates stronger divergence over the western Pacific and Bay of Bengal compared to El Nino.
  • This explains why Bay of Bengal region (close to western Pacific) has fewer cyclones during an El Nino Modoki.
  • On the other hand, there is large convergence over the Arabian Sea during an El Nino Modoki explaining the large number of cyclones in that region

Walker cells

  • El Nino Modoki brings only fewer number of cyclones in the Bay of Bengal is because one of the two descending limbs of the Walker Cell is over the western Pacific and Bay of Bengal.
Asending limbDescending limb
brings rain.causes dry conditions not conducive for cyclone formation
  • Only post-monsoon and pre-monsoon periods were chosen for the study.
  • Because Cyclones usually do not form during monsoon season.

Why don’t cyclones form during monsoon?

  1. Since the Atmospheric parameters — low-level relative vorticity, mid-tropospheric relative humidity, vertical wind shear — are not at values conducive for cyclone formation during monsoon.
  2. Second, during monsoon there is strong zonal (latitudinal) wind in the form of a jet at lower levels and this is not conducive for cyclone formation as the vertical shear between lower and upper troposphere will not be minimum.
  3. Finally, the sea surface temperatures are too low for cyclogenesis.

Monsoon: Tibetan Plateu and ENSO

  • The heating of the Tibetan plateau correlated well with rainfall over India from May 20 to June 15 when the monsoon was setting in.
  • vast Tibetan plateau gets warmed during the summer months, and it heats the air above.
  • The air rises and creates and an area of low pressure.
  • That belt of low pressure sucks in moisture from the oceans, thus initiating the monsoon.
  • Temperature of the tropical Pacific Ocean’s surface waters near the international dateline, known as the El Nino-Southern Oscillation (ENSO), also strongly influenced rainfall over central India and its west coast during the early and late phases of the monsoon.

Ocean Related

Sagar Nidhi

Sagar Nidhi

  • Oceanographic Research Vessel,
  • belongs to National Institute of Ocean Technology (NIOT), Chennai.
  • Sagar Nidhi helps NIOT in technology demonstration work on deep-sea mining and tsunami studies.
  • It is an ice class vessel= can cut through thin ice of 40 cm depth.
  • It is the first Indian vessel to have gone to Antarctic waters.
  • The ship is the first of its kind in the country and has been used several times for launching and retrieval of remotely operable vehicle (ROV) and the nodule mining system.

Dynamic positioning system (DPS)

  • is a computer-controlled system which automatically maintains the position of the ship at mid-sea
  • sea-state 5 — when the wave height is 4–5 metres
  • DPS, even at sea-state 5 — when the wave height is 4–5 metres — the ship’s position can be fixed to within a variation of less than 50 metre
  • Ships that do not have a DPS can be manoeuvred only manually so that the position of the ship is fixed up to deviations of 200-300 metres.
  • This feature comes in useful when deploying remotely operable vehicles, Tsunami alert systems etc, which require the ship to maintain a fixed position for a very long time.

Polymetallic nodules

Nodules

  • also called manganese nodules,
  • They’re rock concretions, lie on the sea-bottom sediment.
  • Why important for India? because they contain cobalt (medical treatment) and nickel (making batteries) and India doesn’t have any terrestrial source of these metals.
  • Nodules have been found in all the oceans and even in lakes. However, not all nodule fields are worth mining from commercial point of view.
  • They can occur at any depth, but the highest concentrations have been found between 4,000 and 6,000m.
  • Three areas have been selected by industrial explorers: the centre of the north central Pacific Ocean, the Peru Basin in the south-east Pacific Ocean and the centre of the north Indian Ocean.

challenges

  • Nodules on the Indian Ocean bed are found at a depth of about 6,000 metres and the closest point of the nodule fields is at a distance of about 2,500 km off the Kanyakumari coast.
  • National Institute of Ocean Technology (NIOT) has so far tested their machines only up to a depth of 5,000 metres.
  • These machines would harvest and crush the nodules before bringing them to the surface.
  • The challenges of developing the technology do appear formidable — the high pressure of 600 bar that exists at that depth (6,000 m) is one of them.

International seabed authority

  • Autonomous international organization established under the United Nations Convention on the Law of the Sea.
  • HQ: Kingston, Jamaica
  • It grants the exploration rights in Sea.
  • U.K. firm, Lockheed Martin, will soon be taking up mining operations in a 58,000 sq. km area in the Pacific Ocean.
  • India will also be able to harvest the nodules from the seabed in about two years, when the technology is fully developed. India has been a pioneering investor in this research.

Pollution related

Gold Extraction without pollution

  • In traditional method, poisonous cyanide is used for dissolving and extracting the gold locked up in mineral ore
  • But the method is polluting and controversial.
  • Several spills have been recorded over the years from mining sites that use cyanide leaching — putting human lives and the environment at risk.
  • While Europe allows the use of cyanide in mining, some countries like Germany, Czech Republic and Hungary have outlawed it and in 2010, the European Parliament called for these national bans to extend to the continent as a whole.
  • But despite being banned in several countries, it is still used to extract more than 80 per cent of gold around the world.
  • Now an international team of scientists have found a new method: to extract gold using a mixed a sugar (alpha-cyclodextrin) derived from cornstarch
  • It is inexpensive and pollution free.
  • The method could also be used to remove gold from consumer electronic waste.

Nanotech pollution detectors

  • Ammonia is an important component of explosives, fertilisers, and industrial coolants.
  • Hence ammonia detectors are used to check for pollution in the vicinity of urban settlements, such as in rivers, lakes, buildings, etc.
  • Existing Ammonia detectors very expensive, difficult to manufacture.
  • Now scientists have devised a simpler, more portable method to detect ammonia:
  • using ferrimagnetic nanofluids as sensors, They reflect bluer light when exposed to ammonia.

Atom Bicycle generator (USB)

  • “Atom” is brandname of a lightweight bicycle generator,
  • It can power your mobile, lights or any electronic device via USB.
  • It comes with a detachable rechargeable battery pack, meaning the stored energy can be used whenever and wherever you need it.
  • The price point of the Atom [$105] is set for domestic [U.S.] and European markets.
  • 9 out of 20 households in India still use bicycles (Census 2011). This offers a great potential to tap vast amount of energy from these cycles.

Citizen science projects

common bird monitoring of India programme

  • The aim of the programme is to collect data on common Indian birds
  • headquartered in Nashik, collects data on population and distribution of common birds with the help of common men / volunteers.

People’s biodiversity register

  • important person: Madhav Gadgil
  • to usher traditional knowledge systems into mainstream science.
  • The study involved catching and releasing back to the river about 1,500 fish through 146 fishing events.
  • Along with the scientific names, the local names of the fish were also recorded.
  • Also recorded were the names given to pools and river stretches.
  • This really brought the community’s extensive knowledge of the ecosystem to the fore.

Flora and Fauna

Insects’ circulatory system

  • Do ants, earthworms, cockroaches have blood circulation system like vertebrates with hearts and blood vessels?
  • In insects, the blood is called haemolymph= contains hemocyanin instead of hemoglobin found in human blood.
  • Unlike human blood, insect blood does not transport oxygen and hence most insects receive oxygen through the tracheal system.
  • Insect blood flows through the body cavity and makes direct contact with organs and tissues.
  • The body cavity is divided into three compartments by two thin sheets of muscle to facilitate blood circulation in insects.
  • In front of the heart, it is a simple tube without valves that extends up to the head, and ends near the brain.

Why baby leaves are red?

  • colour of new leaves of some plants is not green but while growing after few days they become green. Why?
  • the tropical countries, during the rainy season or in the growing season we can notice the appearance of red-coloured young leaves as we see in mango trees.
  • As the leaves age, the red colour disappears and the leaves become green.
  • Red colouration of these young leaves is due to the development of anthocyanin pigments.
  • development of anthocyanin pigments in young leaves is a kind of adaptation and helps in following ways:
  1. Anthocyanins act as a “sunscreen” by protecting cells from UV or blue-green light and thereby protect the young leaves from too much light.
  2. The red colour due to the presence of these pigments may hide leaves from red-colour-blind herbivores (the aphid insects), which would be especially important in young leaves
  3. Red colour may signal unpalatability to herbivores, since phenols are often produced along with the anthocyanins.
  4. The anthocyanins may also deter or kill fungus and thereby can protect the young leaves from fungal attack.

Toe control

  • Unlike fingers, why are we unable to individually control our toes?
  • Especially the thumb and the little finger, each has 4 separate muscles in the hand called the thenar and hypothenar muscles respectively for finer movements.
  • In contrast, the muscles of the toes except the great toe have a common bulk for their action. Hence when we try to move one toe, they move together.
  • The primary function of the hand is to perform various skills and activities which are supported by the fine movements in the various joints and individual movements of the fingers.
  • But the primary function of the foot is transmission of the body weight and for balancing during various activities. This function doesn’t require individual movements of toes.

Why do ants like sugar?

  • In an ant colony, food is gathered by the foragers who constitute about 10 per cent of the colony members.
  • The foragers might collect the protein-rich food for the queen, when she is actively laying the eggs. Similarly, protein-rich foods are preferred when the colony has a high larval population.
  • When the colony has no larvae, the foragers preferably gather the sugar-rich foods, because adult colonies consuming protein-rich food have extremely high mortality due to protein toxicity.
  • Even if they find a food which is rich in protein but poor in sugars, they extract the sugars and eject the protein as a waste.
  • Hence, it is quite normal to see the foragers attracted towards sugary products (carbohydrates), unless there is a demand for protein by the egg-laying queen or the larvae.

Mock Qs at the end of third part.

For more on science-tech, visit Mrunal.org/snt

Mrunal recommends

  1. (free) NCERT, NIOS, TN-Books 4 History,Geo,Sci
  2. Indian Polity M.Laxmikanth (Hindi | English)
  3. Spectrum: Modern History (Hindi | English)
  4. Maths: Quantam CAT Sarvesh Kumar
  5. Objective General English SP Bakshi
  6. Word Power made Easy -Norman Lowe
  7. Topic wise Solved Paperset by Disha

45 Comments on “[Science-Tech] TheHindu (March2May) (Part 1 of 3): Agriculture, Environment-Biodiversity, Silage, Salt Pump, Sagar Nidhi, El Nino Modoki & more”

  1. cool info, you rocks

  2. thank u mrunal sir :)

  3. Finally guru ji is back on track !!

    Was waiting for dis for past 17 days !!
    Thanks sir !!

  4. Release the strategy of history as well as new GS with elaboration plzzzzz

    1. Hi Amol,
      I am also having History as optional. Can you share your contact so that we can share common ideas. :)

      Thanks,
      Deepak,
      9780144786

  5. thanks a lot Mrunal Sir

  6. Finally you are back on track with Real posts. Been waiting for some like these.

  7. nice article…:)

  8. sir I read ur previous post on GS new syllabus, its very nice. sir pls upload GS mains detailed plan, strategy, Books(for new papers)

  9. sir
    plz suggest some books or material for gs paper (integrity ethics) …

  10. Thnx a lot…for ur help…
    Plz provide a plan and material and tips for history optional .. As provided for socio and pub ad
    Thnx a ton in advance!!

  11. Thnx a lot…for ur help…
    Plz provide a plan and material and tips for history optional .. As provided for socio and pub ad
    Thnx a ton in advance!!

  12. Summer vacation ends.

      1. sir ji apke prologues and parvchans……aag jlaa dete hai andar mai…ek baar to murda bhi uth kar IAS preparation suru kar dega ye sub pad kar…..

        So I request you to keep kicking us with your parvachans at regular intervals…..we are getting addicted to your parvachans…….it doest not matter even if you copy and paste your old satya vachans….

        1. very true :) … thx mrunal sir :)

        2. Be self-motivated.. Don’t wait for external push!!

          1. @Sanjeev..Agree with you but there is no harm in getting an extra push on the top of your own motivation…

  13. Loved it !! thanks a lot for this article.

  14. thanks a million sir

  15. Hi, mrunal, can you provide complied downloads for history along with book list for new syllabus as you did for pub ad and sociology.

  16. thank you mrunal sir, much appreciated.

  17. can’t find words to appreciate you sir
    but still….
    thank you very much

  18. back to the business……….
    HAIL MRUNAL……

  19. Thank u thank u a lot Sir

  20. tx.. a lot sir….

  21. sir please provide some guidance for management optional.

  22. citrus green ds was supposed to originated in china so also k/as……YELLOW DRAGON DISEASE…caused by PSYLLIBIDS

  23. I came to know about Mrunal.org after my 2012 ias mains. I missed 2012 chance, now after that costly loss, I m looking forward to crack this time. Sir your guidance is crucial, keep it up sir. god bless you… good night.

  24. sir ji 2014 strategy………..

  25. Thanks Sir,
    Plz advice which subject to choose as optional (pub ad and geography) and books for GS

  26. hi sir,,, your EL-NINO diagram is absolutly wrong.e.g-in this phenomena ,the eastern part of pacific is more warmer than western part.

    1. yeah…Shivam is right. I was wandering that point.
      El nino is mostly abnormal warming up of eastern pacific coast(cold peru current).

  27. Sir The Posts are Fantastic..
    All Hail MRUNAL SIR… :)
    By the way, sir ji 2014 strategy..plzz

  28. sir,

    plz release the strategy for gs mains 2013 as soon as possible, as you had mentioned before..
    we all are desperately waiting for the same.
    and thank you very much for the science tech material.

  29. Sir in Polymetalic nodule the nearest point is 2500KM fro Kanyakumari Coast.
    It should be 2500m or 2500KM .

  30. El Nino modoki concept is not clear

  31. thanku sir

  32. Nothing so much for a hindi medium aspirant, plz sir provide ur articles in hindi..thanx

  33. thanks for stuffing notes

  34. Can abandoned lands which used for aquaculture be cultivable?

  35. Can abandoned lands, which were used for aquaculture, be cultivable?

  36. how ElNino works – I think it needs a little bit correction. eastern pacific coast gets warmer in ElNino

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