on 02-Oct-2020 (Fri)

Materials such as tungsten diselenide (WSe2) and molybdenum diselenide are being studied keenly for their opto-electronic properties – a combination of optics and electronics. A key property of these materials is photoluminescence, in which the material absorbs light and re-emits it as a spectrum.

Materials such as tungsten diselenide (WSe2) and molybdenum diselenide are being studied keenly for their opto-electronic properties – a combination of optics and electronics. A key property of these materials is photoluminescence, in which the material absorbs light and re-emits it as a spectrum. Researchers from IIT Madras have found a way of enhancing this property about 30 times in tungsten diselenide, by drop-casting gold nanoparticles on to a two-dimensional film. The work is published in Applied Physics Letters.

When an electron jumps from the valence to the conduction band, it leaves behind a shadow called a “hole.” The electron in the conduction band and the hole in the valence band can bind together and form a composite object ( or pseudoparticle) known as an exciton. Photoluminescence in tungsten selenide is a result of such excitons.

When they drop-cast gold nanoparticles on the surface of the monolayer tungsten diselenide, they find that the dark excitons couple to the surface fields generated and recombine to give off light quanta. Thus, the dark excitons are “brightened” with the help of the gold nanoparticles.

“The primary excuses for not including females in your research was first that hormones just made everything so complicated that you were... going to have a difficult time if you tried to study the brain in females animals,” said Shansky, explaining the conventional wisdom at the time.

The sleep aid Ambien is a famous example: it caused more side effects in women than in men.

Water finds its way to the petals where the polypyrrole material coating on the flower turns the water into steam. Impurities naturally separate when condensed in this way.

Rice blast, caused by a fungus Magnaporthe oryzae, is one of the major diseases of the rice crop. Now, researchers from ICAR-National Rice Research Institute (NRRI), Odisha have mapped out the diverse genes in rice that help in disease resistance.

ICICI Bank has announced the introduction of usage of satellite data—imagery from earth observation satellites—to assess credit worthiness of its customers belonging to the farm sector.

The bank, the first in India and among few globally, will use satellite data to measure an array of parameters related to land, irrigation and crop patterns and use it in combination with demographic and financial parameters to make faster lending decisions for farmers, it said.

“This use of technology helps farmers with existing credit to enhance their eligibility, while new-to-credit farmers can now get better access to credit,” it added.

Additionally, since the land verification is done in a contactless manner with the help of satellite data, credit assessments can be done within a few days as against the industry practice of upto 15 days.

The bank has been using satellite data for the past few months as a pilot basis in over 500 villages in Maharashtra, Madhya Pradesh and Gujarat and will now scale it up to over 63,000 villages across the country in two to three months.

A decision to increase the Fair and Remunerative Price (FRP) of sugarcane for 2020-21 marketing year (October-September) was taken in the meeting of the Cabinet Committee on Economic Affairs (CCEA) held in New Delhi.

The FRP, which is determined under Sugarcane (Control) Order, 1966, is the minimum price that sugar mills have to pay to sugarcane farmers.

Major sugarcane producing States such as Uttar Pradesh, Punjab and Haryana fix their own sugarcane price called ‘State advisory prices’ (SAPs), which are usually higher than the Centre’s FRP.

‘Uber for tractors’: Government to launch app to aid farmers

theorems and truths correspond—that is, an isomor phism exists between theorems and some portion of reality.

There is a "lower level" of our isomorphism—that is, a mapping between the parts of the two structures:

• P <==> plus
• q <==> equals
• - <==> one
• -- <==> two
• ---<==> three etc.

This symbol-word correspondence has a name: interpretation.

The word "isomorphism" applies when two complex structures can be mapped onto each other, in such a way that to each part of one structure there is a corresponding part in the other structure, where "corresponding" means that the two parts play similar roles in their respective structures.

in a language, when we have learned a meaning for a word, we then make new statements based on the meaning of the word. In a sense the meaning becomes active, since it brings into being a new rule for creating sentences. This means that our command of language is not like a finished product: the rules for making sentences increase when we learn new meanings. On the other hand, in a formal system, the theorems are predefined, by the rules of production. We can choose "meanings" based on an isomorphism (if we can find one) between theorems and true statements. But this does not give us the license to go out and add new theorems to the established theorems. That is what the Requirement of Formality

When different aspects of the real world are isomorphic to each other (in this case, additions and subtractions), one single formal system can be isomorphic to both, and therefore can take on two passive meanings.

The idea of well-formed strings in any formal system is that they are those strings which, when interpreted symbol for symbol, yield grammatical sentences. (Of course, it depends on the interpretation, but usually, there is one in mind.)

Suppose that in an excavation somewhere, we actually did discover some mysterious formal system. We would try out various interpretations and perhaps eventually hit upon one which seemed to make every theorem come out true, and every nontheorem come out false.

We use the word "all" in a few wayswhich are defined by the thought processes of reasoning. That is, there are rules which our usage of "all" obeys. We may be unconscious of them, and tend to claim we operate on the basis of the meaning of the word; but that, after all, is only a circumlocu tion for saying that we are guided by rules which we never make explicit. We have used words all our lives in certain patterns, and instead of calling the patterns "rules", we attribute the courses of our thought processes to the "meanings" of words. That discovery was a crucial recognition in the long path towards the formalization of number theory