NUCLEAR BATTERIES – Abstracts and Seminar Topics

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NUCLEAR BATTERIES

Micro electro mechanical systems

(MEMS) comprise a rapidly expanding research field with potential applications varying from sensors in air bags, wrist-warn GPS receivers, and matchbox size digital cameras to more recent optical applications. Depending on the application, these devices often require an on board power source for remote operation, especially in cases requiring for an extended period of time. In the quest to boost micro scale power generation several groups have turn their efforts to well known enable sources, namely hydrogen and hydrocarbon fuels such as propane, methane, gasoline and diesel.

Some groups are develo ping micro fuel cells than, like their micro scale counter parts, consume hydrogen to produce electricity. Others are developing on-chip combustion engines, which actually burn a fuel like gasoline to drive a minuscule electric generator. But all these approaches have some difficulties regarding low energy densities, elimination of by products, down scaling and recharging. All these difficulties can be overcome up to a large extend by the use of nuclear micro batteries.

Radioisotope thermo electric generators (RTGs) exploited the extraordinary potential of radioactive materials for generating electricity. RTGs are particularly used for generating electricity in space missions. It uses a process known as See-beck effect. The problem with RTGs is that RTGs don’t scale down well. So the scientists had to find some other ways of converting nuclear energy into electric energy. They have succeeded by developing nuclear batteries.

NUCLEAR BATTERIES

Nuclear batteries use the incredible amount of energy released naturally by tiny bits of radio active material without any fission or fusion taking place inside the battery. These devices use thin radioactive films that pack in energy at densities thousands of times greater than those of lithium-ion batteries. Because of the high energy density nuclear batteries are extremely small in size. Considering the small size and shape of the battery the scientists who developed that battery fancifully call it as “DAINTIEST DYNAMO”. The word ‘dainty’ means pretty.

Types of nuclear batteries

Scientists have developed two types of micro nuclear batteries. One is junction type battery and the other is self-reciprocating cantilever. The operations of both are explained below one by one.

JUNCTION TYPE BATTERY

The kind of nuclear batteries directly converts the high-energy particles emitted by a radioactive source into an electric current. The device consists of a small quantity of Ni-63 placed near an ordinary silicon p-n junction – a diode, basically.

WORKING:

As the Ni-63 decays it emits beta particles, which are high-energy electrons that spontaneously fly out of the radioisotope’s unstable nucleus. The emitted beta particles ionized the diode’s atoms, exciting unpaired electrons and holes that are separated at the vicinity of the p-n interface. These separated electrons and holes streamed away form the junction, producing current.

It has been found that beta particles with energies below 250KeV do not cause substantial damage in Si [4] [5]. The maximum and average energies (66.9KeV and 17.4KeV respectively) of the beta particles emitted by Ni-63 are well below the threshold energy, where damage is observing silicon. The long half-life period (100 years) makes Ni-63 very attractive for remote long life applications such as power of spacecraft instrumentation. In addition, the emitted beta particles of Ni-63 travel a maximum of 21 micrometer in silicon before disintegrating; if the particles were more energetic they would travel longer distances, thus escaping. These entire things make Ni-63 ideally suitable in nuclear batteries.

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E – WASTE —– ABSTRACT & SEMINARS

admin — Sat, 15 Dec 2012 13:10:00 +0000

ABSTRACT OF E-WASTE

Electronic waste or e-waste is any broken or unwanted electrical or electronic appliance. E-waste includes computers, entertainment electronics, mobile phones and other items that have been discarded by their original users. E-waste is the inevitable by-product of a technological revolution. Driven primarily by faster, smaller and cheaper microchip technology, society is experiencing an evolution in the capability of electronic appliances and personal electronics. For all its benefits, innovation brings with it the byproduct of rapid obsolescence. According to the EPA, nationally, an estimated 5 to 7 million tons of computers, televisions, stereos, cell phones, electronic appliances and toys, and other electronic gadgets become obsolete every year. According to various reports, electronics comprise approximately 1 – 4 percent of the municipal solid waste stream. The electronic waste problem will continue to grow at an accelerated rate. Electronic, or e-waste, refers to electronic products being discarded by consumers.

Introduction of E-Waste

• E-waste is the most rapidly growing waste problem in the world.• It is a crisis of not quantity alone but also a crisis born from toxics ingredients, posing a threat to the occupational health as well as the environment.

• Rapid technology change, low initial cost, high obsolescence rate have resulted in a fast growing problem around the globe.

• Legal framework, proper collection system missing.

• Imports regularly coming to the recycling markets.

• Inhuman working conditions for recycling.

• Between 1997 and 2007, nearly 500 million personal computers became obsolete-almost two computers for each person.

• 750,000 computers expected to end up in landfills this year alone.

• In 2005, 42 million computers were discarded

• 25 million in storage

• 4 million recycled

• 13 million land filled

• 0.5 million incinerated

IT and telecom are two fastest growing industries in the country.

• India, by 2008, should achieve a PC penetration of 65 per 1,000 from the existing 14 per 1,000 (MAIT)

• At present, India has 15 million computers. The target being 75 million computers by 2010.

• Over 2 million old PCs ready for disposal in India.

• Life of a computer reduced from 7 years to 3-5 years.

• E-Waste: Growth Over 75 million current mobile users, expected to increase to 200 million by 2007 end.

• Memory devices, MP3 players, iPods etc. are the newer additions.

• Preliminary estimates suggest that total WEEE generation in India is approximately 1, 46,000 tonnes per year.

E-waste: It’s implications:

• Electronic products often contain hazardous and toxic materials that pose environmental risks if they are land filled or incinerated .

• Televisions, video and computer monitors use cathode ray tubes (CRTs), which have significant amounts of lead.

• Printed circuit boards contain primarily plastic and copper, and most have small amounts of chromium, lead solder, nickel, and zinc.

• In addition, many electronic products have batteries that often contain nickel, cadmium, and other heavy metals . Relays and switches in electronics, especially older ones, may contain mercury

• Also , capacitors in some types of older and larger equipment that is now entering the waste stream may contain polychlorinated biphenyls (PCBs) .

You can reduce the environmental impact of your E-Waste by making changes in your buying habits, looking for ways to reuse including donating or recycling. Preventing waste to begin with is the preferred waste management option. Consider, for example, upgrading or repairing instead of buying new equipment to extend the life of your current equipment and perhaps save money. If you must buy new equipment, consider donating your still working, unwanted electronic equipment.

This reuse extends the life of the products and allows non-profits, churches, schools and community organizations to have equipment they otherwise may not be able to afford. In South Carolina, for example, Habitat for Humanity Resale Stores, Goodwill and other similar organizations may accept working computers. When buying new equipment, check with the retailer or manufacturer to see if they have a “take-back program” that allows consumers to return old equipment when buying new equipment. Dell Computers, for example, became the first manufacturer to set up a program to take back any of its products anywhere in the world at no charge to the consumer. And, when buying, consider products with longer warranties as an indication of long-term quality.

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Abstracts and Seminar Topics Archives - Askvenkat Books

NUCLEAR BATTERIES – Abstracts and Seminar Topics

E – WASTE —– ABSTRACT & SEMINARS

ABSTRACT OF E-WASTE

Introduction of E-Waste