PFBR: main vessel to be installed soon

The main vessel of the 500 MW Prototype Fast Breeder Reactor that is being constructed at Kalpakkam will be installed anytime during the second half of September, according to Dr. Baldev Raj, Director of the Indira Gandhi Centre for Atomic Research (IGCAR).

The main vessel will house some of the main components of the reactor, like the grid plate (on which the subassemblies containing the fuel will be placed), core support structure, and the primary pipes that will bring the coolant to the grid plate.

Fast breeder reactors have three vessels — the innermost is the inner vessel where the sodium coolant is present, followed by the main vessel and finally the safety vessel. The safety vessel is the outermost vessel. The safety vessel is to contain the sodium coolant in case of any leak in the main vessel.

The main vessel is about 13 metres in diameter, 13 metres in height and about 25 mm in thickness. The small thickness is sufficient because it has to only bear the weight of the coolant (1150 tonnes) and other structures (about 700 tonnes). Also, the pressure inside the main vessel will be low.

This is because the fast breeder reactor uses liquid sodium as a coolant. Sodium becomes liquid at about 100 degree C, and being a metal, the heat transfer property is very good.

Robots for checking

The PFBR reactor is designed to have a gap of 30 cm between the main vessel and safety vessel. “This gap is required for checking the health of the main and safety vessels,” said Dr. Raj.

Highly mechanised robots will be used to check the vessels for any signs of a crack in the vessels through which the sodium can leak. The robots will not be a permanent part of the reactor but will be lowered as and when required. “These must be one of the high tech robots developed in the country,” he said.

Scientists to explore Russia’s Lake Baikal

Russian scientists recently outlined plans for a submarine expedition this month that will for the first time probe the depths of Lake Baikal, a unique ecosystem and the deepest lake in the world.

The expedition is being organised by Artur Chilingarov, a pro-Kremlin member of parliament and an Arctic explorer who led the team of scientists that planted a flag at the bottom of the North Pole in August last year.

“It’s technically very complex,” Chilingarov told reporters in Moscow, explaining that the bottom of Lake Baikal at 1,600 metres (5,249 feet) has never been explored, with previous missions only going down hundreds of metres.

Scientists will collect samples at different depths and hope to document the effects of global warming on the lake, as well as drawing the attention of the Russian government to the need for greater environmental protection.

The mission to Lake Baikal — a UN World Heritage site — will begin on July 29 and will carry out dozens of dives by the Mir-1 and Mir-2 mini-submarines. The mission is being funded by environmental organisations.

Lake Baikal contains around a fifth of the world’s freshwater reserves.

Extraordinary finding of fossilised animals

Extraordinary finding of fossilised animals

Fossilized jaw of a crocodile is displayed at the Smithsonian Research Institute in Panama City. More than 500 fossils of various animals that lived before a land bridge linked North and South America were uncovered recently.

Videogames are now more sophisticated~~>>wath out~~>>

Videogames are getting smarter and more sophisticated. Now virtual enemies improvise during battles, storylines shift based on moral choices and in-game characters send players text messages for help.

Preserving mangroves for fisheries’ health~~~>>it`s a FACT !!

A new study on the Gulf of California concludes that coastal mangroves are essential for the survival of juvenile aquatic organisms. The health of fisheries and the economic well-being of fishermen depend on this.

Train speed >> still guessing ~~~>read this ~~>>

Why are we unable to guess the speed of a train when we stand on the track facing the oncoming train?

When we see a moving train side ways, we guess its speed by the swiftness with which our eyes move along the object by tagging our sight to a point of reference (mostly the engine).

If we see the moving train not necessarily fully sideways but at an angle (say, while approaching), still we can guess its speed by the change in its depth from us because of the binocular vision we have which manifests more effectively at closer distances than at longer distances.

To summarize, we can guess the relative speed of an object by the quickness of change in its position on an ‘apparently’ rigid frame of reference (in the case of a train, it is the distant natural backdrop).

The problem comes when we are directly facing the oncoming train in the line of sight. The initial and final positions of the engine (object) are on the same line of sight.

There is no need for the lateral movement of our eyes. Further, the train might be too farther from us to provide us the binocular vision of the changing depth of engine’s position. In the absence of a need to move our eyes sideways because of the lack of changing positional parameter of the engine over a frame of reference lateral to us and due to poor possibility for the binocular estimation of the positional depth of the engine from us, we are unable to evaluate the speed of the on coming train when we face it in its line of motion.

Managing root wilt in betelvine >> see it ~~>

In India betelvine is grown in an area of 40,000 hectares, of which Tamil Nadu occupies about 6,000 hectares. The annual revenue earned from the crop is estimated to be around Rs. 700 crores. Betelvine leaves are exported to United Arab Emirates, Oman, Bahrain, Egypt, Pakistan, Kenya and Bangladesh.

In India annual betelvine leaf production is estimated to be around 25,314 million leaves, of which Tamil Nadu's production is around 11,766 million leaves.

Number of diseases The crop is attacked by diseases such as root wilt, leaf rot, vine seedling wilt, bacterial leaf blight, alternaria, anthracnose, rust and powdery mildew.

Among these root wilt is a serious infestation which causes 30-100 per cent loss to the crop.

Occurrences of root wilt are found throughout the year and are severe during October to February. Varieties Karoora Vellaikodi and Pacchaikodi are most susceptible.

Symptoms

The leaves and shoots turn yellow, wither and finally dry. In newly disease affected plant vines, young shoots are infested first. Gradually, the disease spreads through older roots and ultimately reaches the foot or collar region of the plant. In a disease affected plant, the whole underground portion gets completely rotten.

Management

-Growing moderately resistant varieties of betelvine such as Sirugamani-1 (SGM-1).

- Selection of disease free seedling vines for planting. - Treating the seedlings by dipping them in Bordeaux mixture (0.25 per cent) + 0.5g streptocycline for 10 minutes. - Drenching the soil with 0.5 per cent Bordeaux mixture in the planted rows of vines.

-Applying biocontrol agents such as Trichoderma viride at 1 kg mixed in 100 kg of FYM + 10 kg neem cake once in three months per year to the vines.

- Spraying with 0.25 per cent Bordeaux mixture at 15 days interval at four times to check leaf rot.

-Avoid over usage of groundnut cake in the vine garden and remove all the infested leaves fallen on the ground. This practice should be continued because these leaves act as a source of disease spread.