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Post by Dr. Yatri Thor on Oct 17, 2014 2:13:56 GMT 5.5
Bio again
Fruits are classified into two groups.
One, climatric and other, non-climatric.
Climatric types are those that ripen even after harvest, for example, banana. The non-climatric types do not ripen after harvest, for example, grapes. The climatric fruits like banana need an external assistance for ripening them. Scientifically after harvest ethylene gas is used in godowns to hasten banana ripening. While on the plant ethylene hormone is released naturally by the plant to ripen the fruit. Raw banana fruit is firm and not peelable since the cell cementing material is made of non soluble calcium pectin. On ripening the non soluble pectin will become soluble and hence the softness. Similar, before ripening the “starch” a complex sugar will transform into simple sugars on ripeningthus creating inter cellular void which makes peeling easier.
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Post by Dr. Yatri Thor on Oct 18, 2014 14:34:05 GMT 5.5
Hybrid desalination plant at Kalpakkam
Seawater is made to flash evaporate in 39 stages through a small and controlled temperature drop of just 2 degrees per stage - Multi-Stage Flash (MSF) evaporation - the world’s largest hybrid seawater desalination plant coupled to an existing nuclear power plant the Madras Atomic Power Station (MAPS).- deploys both multi-stage flash (MSF) evaporation and reverse osmosis (RO) membrane separation technologies.- flash evaporation – heating at high temperature high pressure and then pressure drop.
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S&T
Oct 18, 2014 14:35:48 GMT 5.5
Post by Dr. Yatri Thor on Oct 18, 2014 14:35:48 GMT 5.5
American scientist invents plastic light bulb
They used plastic polymers and nano materials to generate light that is more energy efficient than current fluorescent lights and is easier on the eye - University in North Carolina - same amount of electricity as LED bulbs and half as much as fluorescent bulbs. The device is made of three layers of white-emitting polymer blended with a small amount of nano-materials that glow when stimulated with electrical current to create bright, perfectly white light similar to the sunlight human eyes prefer.
News from 2013 - you can relate it to LED
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mike
Junior Member
Posts: 29
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S&T
Oct 18, 2014 18:14:33 GMT 5.5
Post by mike on Oct 18, 2014 18:14:33 GMT 5.5
@yatri bro can u help i following matter: "any body writing answers on insights web page? since 25 September onwards they hv made certain changes in their website n i can not see some of the answer,any one tell where hv those answers gone"
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S&T
Oct 18, 2014 18:19:34 GMT 5.5
Post by Dr. Yatri Thor on Oct 18, 2014 18:19:34 GMT 5.5
@yatri bro can u help i following matter: "any body writing answers on insights web page? since 25 September onwards they hv made certain changes in their website n i can not see some of the answer,any one tell where hv those answers gone" yar I am not following insight since last few months.....was busy with work and all, I dont know what happened there. I heard that many people make notes from that website, probably they have made the website private now because of this?
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S&T
Oct 18, 2014 22:54:53 GMT 5.5
Post by Dr. Yatri Thor on Oct 18, 2014 22:54:53 GMT 5.5
Dr. Yatri Thor also throw some light on achievements of indians in science and tech .how to cover dis Its difficult to cover S&T properly, I have not read any coaching material till now. But if I come across some nice material on this, I will share that. Last year I did it only from The Hindu, and almost nothing was asked from it
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S&T
Oct 18, 2014 22:58:55 GMT 5.5
Post by Dr. Yatri Thor on Oct 18, 2014 22:58:55 GMT 5.5
Last year I focused on Indian achievements in Space by ISRO/International projects on Science etc - this is from last year
Scientists and engineers from 27 countries, including India, are pitching for a next-generation gamma-ray telescope that could transform the future of high energy astrophysics. Called the Cherenkov Telescope Array (CTA), the project involves a large array of telescopes to complement existing observatories, the most potent of which orbit the Earth. By building it on land, scientists feel the CTA could be much more sophisticated than orbiting observatories, which have logistical constraints. One proposed northern hemisphere location is in Hanle, in Ladakh, Jammu and Kashmir. Each network will consist of four 23-metre telescopes to image weaker gamma- ray signals, and dozens of 12-metre and 2-4-metre telescopes to image the really strong ones.
Altogether, they will cover an area of 10 sq. km on ground. Gamma rays originate from sources like dark matter annihilation, dying stars and super massive black holes, whose physics is little understood. Such sources accelerate protons and electrons to huge energies and these interact with ambient matter, radiation and magnetic fields to generate gamma rays, which then travel through space.
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Post by Dr. Yatri Thor on Oct 18, 2014 23:48:29 GMT 5.5
Its difficult to cover S&T properly, I have not read any coaching material till now. But if I come across some nice material on this, I will share that. Last year I did it only from The Hindu, and almost nothing was asked from it yes,i agree.science and tech k track karna tough hai. mai sirf kabhi kabhi science reporter delh leta hun,,,but nothing stays in mind..sab kuch evaporate ho jata hai... thats why it is said that the key of success in this exam is revise revise and revise..........
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mike
Junior Member
Posts: 29
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S&T
Oct 19, 2014 12:38:26 GMT 5.5
Post by mike on Oct 19, 2014 12:38:26 GMT 5.5
thanks man.....will c...carry on
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S&T
Oct 19, 2014 14:37:23 GMT 5.5
Post by Dr. Yatri Thor on Oct 19, 2014 14:37:23 GMT 5.5
The humble brinjal’s Bt moment?
Between the U.S. approach of permissions and the European one of prohibitions, there lies a middle path based on precautions, the approach India needs to follow on Bt brinjal. - The moratorium in 2010 had been imposed because of four crucial reasons. First, no State government cutting across party lines and ideologies supported the commercialisation. Second, there appeared to be no overwhelming consensus on it in the domestic and international scientific community. Third, there were concerns that seed supply would be the monopoly — direct and indirect — of one multinational company. Fourth, there appeared to be a persuasive case for more tests and trials under an agreed protocol and under an independent regulatory agency that would inspire wider confidence.
The Genetic Engineering Appraisal Committee, by granting approval to GM trials even before the Supreme Court ruled in the matter, has shown an undue haste. The Centre had filed a response to the report of the Technical Expert Committee (TEC) in April 2014; the apex court is yet to adjudicate on it. The GEAC was quick to point out that the Supreme Court had not imposed a ban on confined field trials. But the comprehensive Parliamentary Standing Committee report on agriculture in 2012 had taken a clear stand against field trials. The TEC called for strengthening the existing regulatory system before granting permission for conducting more field trials. In the absence of a ruling from the Supreme Court, the GEAC steamed ahead with what it thought fit, even as some States were against GM field trials. It clearly went against the opinion of the TEC and parliamentary committee reports and also a letter endorsed by over 250 scientists against field trials of GM crops. “field trials of GM crops are not a government decision. It is a recommendation of the GEAC”. Ever since Bt cotton was granted approval in 2002 without much debate, the issue of transgenic crops has created sharp divisions. The TEC had also recommended a moratorium on field trials of herbicide-tolerant crops until the issue had been examined by an independent committee.
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Deleted
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Post by Deleted on Oct 19, 2014 18:30:31 GMT 5.5
Q&A Environment/S&T
Q.Carbon Capture and Storage (CCS) technologies and their importance.
A. Carbon Capture and Storage (CCS), or carbon sequestration, is a means of separating out carbon dioxide when burning fossil fuels, collecting it and subsequently “dumping” it underground or in the sea.
It is also one of the flexibility mechanisms defined under Clean Development Mechanism (CDM) in the Kyoto Protocol. Carbon capture produces a concentrated stream of CO2 that can be compressed, transported and eventually stored. Some capture technologies are economically feasible under specific conditions while others remain in the research stages. It dds to the over all cost of unit electricity.
As India becomes a considerable emitter in terms of total CO2 CCS acquires importance. Coal is likely to be the mainstay of our energy sources.
The Intergovernmental Panel on Climate Change (IPCC) has concluded that CCS can contribute between 15-55 percent of the cumulative emission reduction effort to 2100, providing it with a central role within a portfolio of low carbon technologies needed to address climate change. International Energy Agency (IEA) says that that CCS is "the most important single new technology for CO2 savings" in both power generation and industry.
India has been taking a cautious approach towards CCS technology. Public understanding of CCS technology in India is very low. Currently, although India favours a sustainable development strategy and wants to bring in counter measures to curb the development of global warming, it still opposes the capture and store method due to the lack of technical parameters. Majorly also due to the economic feasibility, as there is significant potential to reduce the cost and energy demand of CO2 capture and compression processes through technological advancements and investment in research and development.
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Deleted
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Post by Deleted on Oct 19, 2014 18:31:07 GMT 5.5
Q&A
Q. Why was super-resolved fluorescence microscopy in news recently? How is it a breakthrough?
A. The 2014 Nobel Prize in Chemistry has been awarded to a trio of researchers for improving the resolution of optical microscopes: "the development of super-resolved fluorescence microscopy".
The work of the laureates has made it possible to study molecular processes in real time.
Optical microscopes had previously been held back by a presumed limitation: that they would never obtain a better resolution than half the wavelength of light.
This assumption was based on a rule known as Abbe's diffraction limit.
This year's chemistry laureates used fluorescent molecules to circumvent this limitation, allowing scientists to see things at much higher levels of resolution. The key to seeing features on the nano — or billionth-of-a-meter — scale is using molecules that fluoresce, or glow.
In terms of real-world usage, researchers will be able to use this advanced form of technology to explore brain synapses, study the proteins involved in different diseases ( Alzheimer’s, Huntington’s and Parkinson’s diseases for example), and track cell division in embryos. Everything that is going on in the human body will now be understood down to the nanoscale level. Thus, their advance enabled scientists to visualise the activity of individual molecules inside living cells.(Dr.Banerjee taught just now in the class)
JAI SRIRAM'S IAS !!
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Post by Dr. Yatri Thor on Oct 20, 2014 22:20:49 GMT 5.5
Why do we have two nostrils?
Of the two nostrils, one is dominant and the other is not. The dominance is swapped back and forth. More air is inhaled and that too more quickly through the dominant one. The dominant nostril takes in the air rapidly and the other takes in slowly. This is controlled through a cycle called nasal cycle. A chemical substance has to reach the olfactory receptors held deep inside the nose after passing through the mucosa. When the blood vessels beneath the mucosa get more blood, the mucosa becomes thicker and there is less space for air to travel. Hence the mucosa of one of the nostrils stays always swollen compared to the other. Every two to three hours the side changes and the cycle repeat day and night. Some chemicals will be detected well with the high-flow nostril and others with low-flow nostril. The sense of smell varies as per the flow rate and the different absorption rates of the scents (chemicals). The difference in the smell depends on the different absorption rate of the chemicals.
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S&T
Oct 20, 2014 22:22:03 GMT 5.5
Post by Dr. Yatri Thor on Oct 20, 2014 22:22:03 GMT 5.5
Some facts that can be used while writing about Dengue, Malaria etc : UV Light (polarized light) is more predominant during dawn and dusk than infra red light and Mosquitoes are known to be attracted to and using UV light to find damp water sources. Infra red light which is more intense during day time is known to curtail mosquito activity. Change in CO2 concentration in the atmosphere and quiet wind velocities during dawn and dusk might be the triggers for mosquito activities. The odour receptors can detect their target victim at over 100 metres during the night.
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S&T
Oct 22, 2014 22:31:55 GMT 5.5
Post by Dr. Yatri Thor on Oct 22, 2014 22:31:55 GMT 5.5
A better way to make iPSCs?
Embryonic stem cells can develop into most cell types and have much therapeutic potential. However, its method of extraction from human embryos remains highly controversial. Shinya Yamanaka’s invention of induced pluripotent stem cells (iPSC) a Nobel-winning achievement. iPSCs are body (somatic) cells which have been reprogrammed to function like embryonic stem cells, thereby sidestepping the controversial use of killing the embryos while harvesting the stem cells. However, the efficiency of iPSC production is traditionally quite low. Only about 0.01 per cent of the cells successfully become iPSC
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S&T
Oct 22, 2014 22:32:54 GMT 5.5
Post by Dr. Yatri Thor on Oct 22, 2014 22:32:54 GMT 5.5
Injectable polio vaccine, The need of the hour
oral vaccine-derived poliovirus (VDPV) type 2, the virus in question is not the wild type but a vaccine-derived one. Although weakened, the viruses are still alive and can “quite often” undergo genetic changes (back mutate) to cause neuro-virulence (polio). - unlike in the case of the inactivated polio vaccine (IPV) given as injections, no trial was ever conducted on OPV before it was used in USSR and other east European countries.
Vaccine-associated paralytic polio (VAPP) is an adverse reaction to OPV. India had 21 VDPV polio cases in 2009, five in 2010 and seven in 2011 and one in 2012. VDPV can be stopped; thus controlling VDPV is easier than in the case of the wild virus. - VDPV strains can silently circulate (cVDPV) for many months, even 1-2 years before showing up with polio cases.
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S&T
Oct 25, 2014 13:03:41 GMT 5.5
Post by Dr. Yatri Thor on Oct 25, 2014 13:03:41 GMT 5.5
Combating certain types of cancer using photodynamic therapy could become less expensive in the near future with a novel, indigenously-synthesised molecule showing promising results in studies conducted in vitro.
The molecule is a photosensitiser and a derivative of porphyrin. Centre for Cellular and Molecular Biology (CCMB), Hyderabad. In photodynamic therapy which targets certain types of cancer, including skin and stomach, the molecule gets accumulated in cancer cells. When exposed to light, it generates toxic substance which would destroy only the cancer cells. Near infrared light could be used. Therefore the depth of penetration would be less and it would cause less damage as mere exposure to light would not be harmful to normal cells.
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S&T
Oct 25, 2014 13:04:33 GMT 5.5
Post by Dr. Yatri Thor on Oct 25, 2014 13:04:33 GMT 5.5
New four-quark particle at low energy found The particle, named Zc(3900), is a composite of two quarks and two antiquarks.This arrangement differs from what is known about strongly interacting particles. Strongly interacting particles called hadrons are believed to exist in two varieties, three-quark states, named the “baryons” (protons, neutrons, etc) and quark-antiquark bound states called the “mesons” (pions, kaons, etc). These have been the only strongly interacting particles observed and considered by theorists for a long time. Atoms and molecules arise from two kinds of electric charges: positive and negative. But quarks, which are bound together by strong interactions, have three kinds of charges which are characterised by a quantum number called colour (as three kinds of primary colours exist). The theory describing the strong interaction of quarks is called quantum chromodynamics or QCD. Coloured quarks like the North or South Pole of a magnet can never be isolated, and all particles have to be colour neutral. The simplest way to build up particles with these is to consider quark-antiquark pairs or states made of all three quarks
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S&T
Oct 26, 2014 15:57:23 GMT 5.5
Post by Dr. Yatri Thor on Oct 26, 2014 15:57:23 GMT 5.5
Lithium-ion (Li) batteries - Better batteries from rice husk
Lithium-ion (Li) batteries are important for modern technological progress because they power the electronics and hybrid electric vehicles industries, and are an important component of renewable energy methods. However, as advancements in these fields are made, Li batteries are also expected to perform better – such as having higher charge capacity.
At the moment, layers of graphite are used inside Li batteries to store electrical charge from chemical reactions. Silicon has been suggested as a replacement because its charge capacity is about 400 times that of graphite. It is resilient to heat, and easy to store and dispose. And now, scientists from South Korea have proposed an alternate route that is both shorter and eco-friendly. They have proposed to use layers of silicon dioxide, or silica, that rice plants have developed in their husks through years of evolution, as a source of silicon. These silica layers, while forming a protective sheath, are uniquely porous at the nano-scale level to allow air and water ventilation. - 3D nano porous structure. Simple thermal and acidic treatments. Because silicon has low electronic conductivity, researchers then compensatedwith a uniform coating of polydopamine and carbon. Silicon’s atomic layout expands tremendously when Li ions enter it. But the 3D nanoporous structure prevented this from happening by permitting the Li ions to move in a channel-like arrangement without pushing against silicon atoms. This extended the life and performance of the battery.
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S&T
Oct 27, 2014 22:21:23 GMT 5.5
Post by Dr. Yatri Thor on Oct 27, 2014 22:21:23 GMT 5.5
Bio-inspired technology
It learns from the properties and behaviour of plants and animals, particularly their modes of defence and offence, and attempts to produce new technological products, inspired by these properties.
The flowers of the plant cocklebur inspired the Swiss engineer George de Mestral to invent Velcro, the hookand-loop fastener. This plant, which occurs in India, particularly in the Madurai region of Tamilnadu (where it is called Maroolimatthai in Tamil), has a number of small ball-like flowers, each decorated with lots of short pinlike hairs all around, which stick to your socks and clothes.
Millions of tiny hairs that the palm of the lizard’s fingers, or the toe-pads, scientist created tape-based adhesives (like ‘Post It’).
The sharp tip of porcupine quills enables easy penetration. But when it has to be removed by pulling it out, each of the barbs resists by opening up. Scientist idea a biomimetic or bio-inspired polymer patch (a small sheet decorated uniformly with an array of micro- or nano-scale PU-barbed quills) would be useful for the development of mechanically interlocking tissue adhesives or needles, trocars and surgical staples.
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Post by Don Quixote on Oct 29, 2014 17:53:04 GMT 5.5
100th birthday of Dr. Jonas Salk who invented Polio vaccine.Nice story connecting other important events to Salk, including first field trials of vaccines, the HeLa cells (and patient privacy), how Watson & Crick got together (the DNA double helix model), public support in development and use of vaccines, etc. Read at: www.thehindu.com/sci-tech/health/birth-of-salk-and-death-of-polio/article6543219.eceGood to read in the year India was finally declared polio free (U.S was declared so in 1979 after Salk's intervention).
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Post by Lisbeth Salander on Oct 29, 2014 21:06:42 GMT 5.5
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Post by Dr. Yatri Thor on Oct 29, 2014 22:35:19 GMT 5.5
DNA molecules storing data The falling cost of making synthetic DNA may one day open up the possibility of DNA molecules storing data. Researchers have found that DNA has a storage density of 2.2 petabytes, or 2,200 terabytes, per gram, and that it can last tens of thousands of years.
DNA is a long chain, consisting of 4 alphabets (chemical units called bases and referred to as A, G, C and T) put together in a string of sequence - The Goldman group is not the first one to think of DNA as a storage device.
The Hinxton method is that they moved away from the conventional binary (0 and 1) code and used a ternary code system (three numerals 0, 1 and 2 using combinations of the bases A, G, C and T) and encode the information into DNA.
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Post by Dr. Yatri Thor on Oct 31, 2014 0:51:02 GMT 5.5
Self Organising Map (SOM)
IT tool developed to curb dengue, malaria by using data mining. Self Organising Map (SOM), a cluster technique in data mining - CSIR-Indian Institute of Chemical Technology. National Vector Borne Disease Control Programme (NVBDCP) of Union Ministry of Health and Family Welfare. Mosquito-borne diseases like malaria, Japanese encephalitis and dengue.
The technology comprises two dimensions — one relating to the names of the villages and the second focusing on mosquito density, infection, infectivity and parasitic load. Based on these parameters, a complete mapping of the villages could be done in terms of prioritising control parameters. For instance, in a village where parasitic load is heavy, drug administration rather than mosquito control would be the priority.
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S&T
Nov 1, 2014 21:31:25 GMT 5.5
Post by Dr. Yatri Thor on Nov 1, 2014 21:31:25 GMT 5.5
Vortex factor in E. Antarctica glacier meltEast Antarctica which has the world’s largest ice sheet. Forces other than global warming are at play here unlike in Western Antarctica and the Arctic which have seen extensive ice loss in the past decade or two. The Southern Annular Mode (SAM) as one of the reasons for less glacier retreat in recent decades and link a positive phase of SAM to greenhouse gas concentrations and ozone depletion resulting in cooler temperatures over East Antarctica. SAM describes the north-–south movement of the westerly wind belt that circles Antarctica, dominating the middle to higher latitudes of the southern hemisphere. In a positive SAM event, the belt of strong westerly winds contracts towards Antarctica. When the SAM is in a positive mode, it strengthens the westerly winds that circulate around Antarctica during the austral winter. These strong circumpolar winds (known as the polar vortex) effectively lock in cold air and low pressure to the south of them and prevent warmer, more maritime air, influencing the ice sheet from the north. There is less heat exchange between the tropics and the pole. In recent decades the polar vortex has strengthened, leading to cooler temperatures over East Antarctica. These westerly winds drag surface currents and actually take them a little further north. Surface water is replaced by warmer water dragged up from the deep.
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