IISER - Current Affairs Questions and Answers

ANSWER: Cathodes

Explanation:
Scientists at the Indian Institute of Science Education and Research in Kolkata have found a fresh way to produce cathode for solar cells.

• IISER researchers use human hair to produce effective, metal-free cathodes for use in solar cells
• This is the first time that a bio-waste derived electrode has been used as a cathode na quantum dot sensitised solar cell device
• The graphitic porous carbon cathode shows an excellent performance to ensure visible sunlight is converted to electricity, which is higher than commercially activated carbon cathodes
• This offers higher efficiency for converting visible sunlight to electricity
• The cathode was found to generate high open-circuit voltage at par with conventional platinum and activated carbon cathodes
• Producing graphitic porous carbon cathode using human hair is simple, quick and affordable
• Unlike the other synthetic porous carbons, no physical or chemical activation process or templates were required to produce the pores of 2-50 nanometres diameter
• The porosity along with the high surface area to volume ratio plays an important role in adsorption-desorption of electrolyte
• Cleaned and dried human hair was first treated with sulphuric acid at 165 degrees C for 25 minutes to attain pre-carbonisation
• It is then heated to different temperatures in the presence of inert gas for 6 hours to carbonise and ensure better electrical conductivity for efficient charge transfer.

ANSWER: Increases

Explanation:
Hermann Minkowski and Max Abraham came up with opposite equations that both seemed to be supported by polar experimental data, as far as the question of what happens to the momentum of light is concerned. Using indigenous equipment, IISER scientists have found the former was correct and light does enter another medium and gain momentum. At angles close to TIR, the water surface was discovered to be bent upwards due to the pressure exerted by the photon beam and was spread to 100 times in excess of the area of the pumped laser. The analysis demonstrated that the light particles actually gained momentum. The equipment designed can also help in the development of better biosensors, lab-on-chip devices, easily reconfigurable lenses and molecular imaging tools.