SCIENCE & TECHNOLOGY

Gen-next of mobile phones
G
eneration
next of mobile phones gets smarter! Smart phones, as these gizmos are called, are the latest lifestyle devices, which have a lot more to them than SMS and voice capability — they have PC like functionality.

Radon radiation in houses
S.P. Gupta

Radon gas is a significant source of exposure to natural radiation. This is because the immediate decay products of radon-222 are radionuclides with short half-lives, which attach themselves to fine particles in the air, are inhaled, irradiate the tissues of the lung with alpha particles, and increase the risk of lung cancer. The same is true of radon-220 (thoron), but the degree of exposure of the lung is much less.

Prof Yash Pal

Prof Yash Pal

UNDERSTANDING THE UNIVERSE
WITH PROF YASH PAL

What is the effect of pressure in a pressure cooker on the boiling
point of water?

The usefulness of a pressure cooker derives from the fact that the temperature inside can be raised above the normal boiling point of water. This is the reason that things cook faster in a pressure cooker. This is particularly useful when you are at a high altitude and the atmospheric pressure is low.


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Gen-next of mobile phones

Generation next of mobile phones gets smarter! Smart phones, as these gizmos are called, are the latest lifestyle devices, which have a lot more to them than SMS and voice capability — they have PC like functionality.

Aimed at catering to present day’s upbeat professionals, these smart phones converge multiple applications — cell phone, e-mail device and a personal organiser — all in one.

Elaborating on how smart these smart phones could get, Sudhin Mathur, GM - India, Sony Ericsson says, "With a smart phone you can do a host of activities like surf the net, send mails, play games, organise your day and even hold conference calls. Smart phones usher in the era of convergence."

Sanjeev Sharma, Managing Director, Nokia customer and market operations in India agrees, "While most mobile phones can receive data, it is usually only in the form of text pages limited to around 150 characters. On the other hand smart phones enable users to browse web, send e-mail, click photos and do personal information management (PIM)."

The smart phone industry targets a gamut of people ranging from tech-savvy professionals to extensive travelling entrepreneurs and businessmen.

Pointing that smart phones are relatively new phenomena for Indian markets, Mathur says, "The target audience for these phones are professional pioneers with good earning potential. Those who have an emotional attachment to technology in that they often adopt the first or newest thing in the market."

Sanjeev Sharma could not agree more as he says, "smart phones are lifestyle enhancers that are targeted at mobile professionals who want to constantly have access to their work through e-mails and calls."

Experts agree that though PC-like gadgets, for example Personal Digital Assistant (PDAs) already exist in market they are quick to point out that while PDAs tend to centre on PIM, smart phones are built around voice calls.

"Most PDAs have focused on delivering organiser functions really well but few have wireless capability that all mobile phones have even if it is only for voice calls," says Sharma though he concedes boundaries between PDAs and smart phones were blurring.

Market experts believe smart phones are increasingly replacing PDAs as they incorporate all the standard features of PDAs.

However, they do agree that smart phones have certain shortcomings that need to be rectified. Battery life and security are two major issues clouding the smart phone capabilities.

As Sharma admits, "battery life is one key issue as a device that uses both voice and data communications ends up drying out the battery faster."

"This, however, will be solved with new battery technology," he adds.

"Security is still seen as a concern as some corporations may not make sufficient end-to-end security from mobile device back to the corporate network, " he says.

Telecom gurus term smart phones as marvel of technology but admit that currently the product is priced towards high-end. Nevertheless they believe in years to come smart phones will change the way people communicate in a big way.

"Although sales of smart phones seem to be picking up in India, the market share is still very less because of their high price," says Sudhin Mathur.

But he adds, "it is likely that all phones will be smart to a certain degree, as technological improvements make it much easier to include extra features in them."

"Further features in smart phones could possibly include more enhancement in security levels, applications support, performance, memory capacity etc," says Sharma as he speculates that mobility will change the way people work — freeing them to work on their own terms regardless of time and place. — PTI
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Radon radiation in houses
S.P. Gupta

Radon gas is a significant source of exposure to natural radiation. This is because the immediate decay products of radon-222 are radionuclides with short half-lives, which attach themselves to fine particles in the air, are inhaled, irradiate the tissues of the lung with alpha particles, and increase the risk of lung cancer. The same is true of radon-220 (thoron), but the degree of exposure of the lung is much less.

When radon gas enters the atmosphere from the ground, it disperses in the air, so concentrations out of doors are low. When the gas enters a building, predominantly through the floor from the ground, the concentration of activity builds up within the enclosed space (figure 1).

If buildings are well ventilated this accumulation of radon will not be marked. However, in many — generally colder — countries, buildings are constructed with more emphasis on retaining heat and preventing droughts. They are, therefore, often poorly ventilated, and radon concentrations indoors can be many times higher than those outdoors.

Radon concentrations in buildings are also very dependent on the local geology and can vary a great deal between different parts of a country and even from building to building in the same area.

The worldwide average annual effective dose from the decay products of radon is estimated to be about 1.2mSv. There are, however, pronounced variations about this value, in some countries (like Finland) the national average is several times higher, and in particular homes in many countries occupants have received effective doses of the order of hundreds of mSv in a year. Given this, International Commission on Radiological Production (ICRP) and International Atomic Energy Agency (IAEA) have recommended the use of Action Levels (expressed in Bq per meter cube) above which householders are advised to reduce radon levels in their homes. Typically these Action Levels should be in the range 200-600Bq per meter cube, which is about 10 times the average value for the radon concentration in homes.

Anyone finding high radon levels in their homes can reduce it by preventing air from the ground entering the building. The most effective way to do so is to reduce the air pressure under the house with a small fan. This circumstance is an example of intervention, in the ICRP sense, to reduce human exposure to ionising natural radiation in houses.

The writer is from Physics Department, Kurukshetra University.
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UNDERSTANDING THE UNIVERSE
WITH PROF YASH PAL

What is the effect of pressure in a pressure cooker on the boiling
point of water?

The usefulness of a pressure cooker derives from the fact that the temperature inside can be raised above the normal boiling point of water. This is the reason that things cook faster in a pressure cooker. This is particularly useful when you are at a high altitude and the atmospheric pressure is low.

So the answer to your question is that at higher pressure water boils at higher temperature. A regulated increase of pressure inside is ensured by the weight that is put over the nozzle in the lid of the pressure cooker. Too high a pressure lifts the weight allowing some steam to escape.

Does the boiling point of water increase or decrease with impurities?

Boiling point of water increases with impurities. I might also mention here that the freezing point of water decreases with impurities. You must have noticed that you can melt ice by pouring salt on it. Incidentally this is the method used to melt away sheet ice on roads in cold winters in America and other cold countries. You must have also noticed that traditional Kulfi makers put salt on the ice surrounding the containers of liquid Kulfi mix. Melted water is as cold as the ice and has a better contact with the Kulfi containers.

Why do swimmers wear special headgear during swimming competitions?

When you are in a serious competition you want to reduce as much friction as possible. During swimming as also during cycling when you have to plow through water or air it is helpful to wear things that would reduce the surface friction as much as possible. That is the reason you wear caps and dresses that can allow you to glide through. Even the surface quality of the fabric can make a difference after you have done as much as possible to make your body and limbs perfectly streamlined, while presenting minimum area in the direction of your movement.

It is true that during swimming you might want to protect your hair from bleaching by the effect of chlorine. But that may not be the primary reason for the design of your apparel.

How do small ants reach far-away eatables?

Ants have amazing capabilities. They have a keen sense of smell. A wandering ant might find a good source of food. Unlike us humans and many other species it does not sit down to devour it. It immediately makes its way to the colony to tell other ants. On the way back it lays down a trail of odorous matter to enable it and other ants to retrace the path using their sense of smell. I do not know how it convinces fellow ants that its find is rich and tasty enough to exploit in concert. Perhaps it carries back a sample.

And then they come in numbers and pounce upon the find. The numbers that congregate depends on the quantity of the find available. If something is large and yet portable, like a dead insect, ants collaborate in carting it away. They would not be able to do it without the capability to laying down the trail, which their sense of smell can follow.

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