Physics

The Wet Bulb temperature is the temperature of adiabatic saturation. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow.

Wet Bulb temperature can be measured by using a thermometer with the bulb wrapped in wet muslin. The wet bulb temperature is always lower than the dry bulb temperature but will be identical with 100% relative humidity (the air is at the saturation line).

-The Dry Bulb Temperature refers basically to the ambient air temperature. It is called “Dry Bulb” because the air temperature is indicated by a thermometer not affected by the moisture of the air. Dry-bulb temperature can be measured using a normal thermometer freely exposed to the air but shielded from radiation and moisture.

Statement 1 is correct. Water has a much higher heat capacity than air, meaning the oceans can absorb larger amounts of heat energy with only a slight increase in temperature.

Water’s specific heat capacity is 4200 Jkg-1K-1 and Air’s is 993 Jkg-1K-1 therefore water has 4.23 times more specific heat capacity.

The specific heat capacity is the amount of energy that must be added, in the form of heat, to one unit of mass of the substance in order to cause an increase of one unit in its temperature.

Statement 2 is incorrect. Water is an unusual liquid and has unique properties. Water does indeed expand when warms, and it contracts when it cools, but not at all temperatures. An oddity occurs between 4 and 0 degrees Celsius (about 40- and 32-degrees Fahrenheit).

Between the temperatures of 32 F (0 C) to 40 F (4 C), liquid water actually contracts with increasing temperature.

Explanation: When rubbers bands are twisted and untwisted, it produces a cooling effect. This is called the “elastocaloric” effect, and researchers have suggested that it can be used in a very relevant context today.

 Researchers from multiple universities, including Nankai University in China, have found that the elastocaloric effect, if harnessed, may be able to do away with the need of fluid refrigerants used in fridges and air-conditioners.

 These fluids are susceptible to leakages, and can contribute to global warming. In the elastocaloric effect, the transfer of heat works much the same way as when fluid refrigerants are compressed and expanded.

 When a rubber band is stretched, it absorbs heat from its environment, and when it is released, it gradually cools down.

 In order to figure out how the twisting mechanism might be able to enable a fridge, the researchers compared the cooling power of rubber fibres, nylon and polyethylene fishing lines and nickel-titanium wires.

 They observed high cooling from twist changes in twisted, coiled and super-coiled fibres.

A rainbow is a meteorological phenomenon that is caused by reflection,

refraction and dispersion of light in water droplets resulting in a spectrum of light

appearing as a circular arc in the sky. It is often visible after rainfall due to highly humid

atmosphere and absence of air pollution. The position of the sun and the raindrops in

relation to the observer need to be just right for a rainbow to form:

• The sun needs to be behind the viewer
• The sun needs to be low in the sky, at an angle of less than 42° above the horizon.

The lower the sun in the sky the more of an arc of a rainbow the viewer will see

• Rain, fog or some other source of water droplets must be in front of the viewer

The size of the raindrops does not directly affect the geometry of a rainbow, but mist or fog

tends to disperse the effect more. Rainbows only appear semi-circular over level ground at

sunrise or sunset, when the sun is exactly on the horizon, the majority of the time a smaller

segment of an arc is seen.

Optical fibre is a device which works on the principle of total internal

reflection by which light signals can be transmitted from one place to another with

negligible loss of energy.

Double rainbow.

Statement 1 is correct: Double rainbows are formed when sunlight is reflected twice

within a raindrop with the violet light that reaches the observers eye coming from the

higher raindrops and the red light from lower raindrops.

Statement 2 is correct: A key feature of double rainbows is that the colour sequence in

the second rainbow is reversed, ROYGBIV instead of VIBGYOR order in primary rainbow.

Polarimetry is a sensitive, nondestructive technique for measuring the

optical activity exhibited by inorganic and organic compounds.

• A compound is considered to be optically active if linearly polarized light is rotated

when passing through it.

• A team of astronomers has discovered that the closest known brown dwarf, Luhman

16A, shows signs of cloud bands similar to those seen on Jupiter and Saturn.

• The researchers used an instrument on the Very Large Telescope in Chile to study

polarised light from the Luhman 16 system. Polarisation is a property of light that

represents the direction that the light wave oscillates.

• The polarimetry technique is not limited to brown dwarfs. It can also be applied to

exoplanets orbiting distant stars. The atmospheres of hot, gas giant exoplanets are

similar to those of brown dwarfs

Polycrack technology is world’s first patented heterogeneous catalytic

process which converts multiple feed stocks into hydrocarbon liquid fuels, gas, carbon

and water. Polycrack Plant can be fed with all types of Plastic, Petroleum sludge, Unsegregated

MSW (Municipal Solid Waste) with moisture up to 50%, E–Waste, Automobile

fluff, Organic waste including bamboo, garden waste etc., and Jatropha fruit and palm

bunch.

Polycrack has the following advantages over the conventional approach of treating solid

waste:-

• Pre-segregation of waste is not required to reform the waste. Waste as collected can

be directly fed into Polycrack.

• It has high tolerance to moisture hence drying of waste is not required.
• Waste is processed and reformed within 24 hours.
• It is an enclosed unit hence the working environment is dust free.
• Excellent air quality surrounding the plant.
• Biological decomposition is not allowed as the Waste is treated as it is

received.

• The foot print of the plant is small hence the area required for installing the plant is

less when compared with conventional method of processing.

• All constituents are converted into valuable energy thereby making it Zero Discharge

Process.

• Gas generated in the process is re-used to provide energy to the system thereby

making it self-reliant and also bring down the operating cost.

• There is no atmospheric emission during the process unlike other conventional

methods except for combustion gases which have pollutants less than the

prescribed norms the world over.

• Operates around 450 degrees, making it a low temperature process when compared

with other options.

• Safe and efficient system with built-in safety features enables even an unskilled user

to operate the machine with ease.

• Low capital cost and low operating cost.
• Fully automated system requires minimum man power.

NOTE: A patent is defined as a statutory privilege granted by the government to inventors,

and to other persons deriving their rights from the inventor, for fixed years, to exclude other

persons from manufacturing, using or selling a patented product or process.

• Hence a patent can be for a process or for a product. There is strict divergence

between product and process patent regimes. The developed countries follow

product patent system. On the other, process patent system is preferred by the

developing world.

• The two systems are known for their different levels of protection to inventors. Under

a process patent, the patent is granted for a particular manufacturing process, and

not for the product itself.

• Any other person can produce the same product through some other PROCESS,

modifying the various parameters. The implication is that there will be more than

one producer for the same product because of the possibility of different process for

the manufacturing of the product.

A new, curious mineral has been discovered inside a diamond unearthed from a mine in South Africa.

 The mineral has been named goldschmidtite, after Victor Moritz Goldschmidt, the Norwegian scientist acknowledged as the founder of modern geochemistry.

 Goldschmidtite has an unusual chemical signature for a mineral from Earth’s mantle, according to the University of Alberta, a student of which discovered it.

 While the mantle is dominated by elements such as magnesium and iron, goldschmidtite has high concentrations of niobium, potassium and the rare earth elements lanthanum and cerium.

 PhD student Nicole Meyer found a single grain of the mineral in the diamond, unearthed in Koffiefontein, South Africa.

 The university described it as dark green and opaque.