SCIENCE & TECHNOLOGY


Electronic waste needs proper management
Deepak Bagai
I
N the past few years, technology advances in electronics have boosted the economy and improved the general lifestyle of a common man. The ever-growing dependence on electronic products has paved the way for an emerging environment concern called “Electronic Waste”.

Trends
Data storage breakthrough
IBM scientists have found a way to cram unprecedented amounts of information onto magnetic tapes in a breakthrough it heralded this week as a data-storing boon to businesses for years to come.

Prof Yash Pal

Prof Yash Pal

THIS UNIVERSE
PROF YASH PAL
If we drink coffee or tea after eating sweets, there is no sweetness left in these drinks. Why is it so?


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Electronic waste needs proper management
Deepak Bagai

IN the past few years, technology advances in electronics have boosted the economy and improved the general lifestyle of a common man. The ever-growing dependence on electronic products has paved the way for an emerging environment concern called “Electronic Waste”.

Electronic equipments contain hazardous material, which can affect human health, and environment, if not properly managed. “Electronic Waste” refers to old, outdated computers, laptops, TVs, cellular phones, mp3 players, telecommunications equipment, instruments, toys, and medical devices etc. Presently, electrical and electronic equipment are being disposed of in landfill sites. The majority of the equipment would contain material that could be recovered and reused for new product development.

Electronic and electrical equipment comprise multiple components, some having toxic substances that can affect human health and environment, if not properly managed. Generally, these hazards occur on account of improper recycling and disposal methods.

Devils in your machine

  • Barium in spark plugs affects the heart.
  • Cadmium in recharge- able batteries affects the kidneys.
  • Chromium in data tapes damages DNA.
  • Lead in CRT screens damages the brain and the liver.
  • Selenium in photo- copiers triggers neu- rological abnormalities.
  • PVC in electronics, when burnt, emits toxic HCl gas.

At present, Cathode Ray Tubes (CRTs) in computer monitors, televisions and other devices are known as “universal waste”. Universal wastes normally do not pose any threat, but are serious hazards to the environment, if disposed of into a solid waste landfill. CRTs have high content of cancer causing elements, such as lead, barium, phosphor and other heavy elements. Disposing of CRTs without precaution can release toxins into the soil, air and groundwater.

There are a number of harmful substances (metals) found in e-waste. Arsenic is found in small quantities in the form of gallium arsenide in light emitting diodes. Arsenic is a poisonous metallic element and chronic exposure to it can lead to skin diseases and lung cancer.

Barium is a metallic element used in sparkplugs, fluorescent lamps and in vacuum tubes. It generates poisonous oxides in contact with air. Exposure to barium can lead to muscle weakness, liver and heart problems. Beryllium found in power supply boxes contains cancer-causing agents, resulting in lung cancer.

Cadmium is present in Rechargeable NiCd-batteries, CRT screens, printer inks and toners. Cadmium components absorbed through respiration, seriously affect the kidneys.

Chromium, found in data tapes and floppy disks, is used because of high conductivity and anti corrosive properties. Chromium (V1) compounds are irritating to eyes, skin and mucous membranes. It can also result in DNA damage.

Lead is found in CRT screens, batteries and printed circuit boards. It is also used in solder, lead-acid batteries, electronic components and cable sheathing. Exposure to high amount of lead can result in vomiting diarrhoea, appetite loss, abdominal pain, constipation, fatigue and sleeplessness, causing brain and liver damage, if inhaled.

Excessive exposure to Selenium used in photocopying machines can cause selenosis (selenium poisoning), leading to hair loss, nail brittleness, and neurological abnormalities.

Polyvinyl chloride (PVC) is an extensively used plastic in electronic appliances. PVC is harmful as it contains about 55 per cent chlorine, which when burned, gives rise to hydrogen chloride gas. This combines with water, to produce hydrochloric acid and if inhaled, can lead to respiratory problems.

There are a number of valuable substances in electronic waste. Gold, Silver, copper glass, plastic etc. are prestigious materials, which recyclers recover from e-waste. The reuse and recycling of outdated electronic products will minimise the hazardous effects of electronic waste on the environment. Reuse and recycling also boost, energy and resource conservation.

Prevention of waste is a better alternative to waste management. It has been proved that all who produce, distribute, use, and dispose of electronic products have a moral responsibility towards managing electronic waste. Electronic equipment manufacturers have to ensure that products have lesser toxic constituents, more recycled content, and are designed for easy upgrade and disassembling.

A new packaging technology is already on offer at Anadigics, which will enhance its product’s moisture sensitivity level. National Semiconductor reveals that most of its products (except solder) are now lead-free. It has also banned the use of cadmium, mercury and chromium in its products. Actel Corp. also offers lead-free devices. Nokia has already sent the hazardous-substance list to its suppliers.

Electronic product manufacturers are struggling to eliminate lead solder, and other heavy metals as constituents. The Silicon Valley Toxics coalition is planning to pass on the recycling cost onto the customer. Japanese electronic OEMs are becoming strict in the use of environment related substances. Hewlett-Packard has emerged as a leader in designing products for recyclability. In the US e-waste recycling is promoted on the website.Finding methods to keep electronic waste out of landfills is a challenge for all electronics manufacturers, recycling and waste management organisations, government agencies and environment management organisations. The Union Government should draft legislation in this direction. If all consumers plan to phase out their obsolete computers and other electronic products at the same time, the country may face a tsunami of e-scrap. Ultimately, it is the balance of nature, which always holds supreme.

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Trends
Data storage breakthrough

IBM scientists have found a way to cram unprecedented amounts of information onto magnetic tapes in a breakthrough it heralded this week as a data-storing boon to businesses for years to come.

Researchers at IBM’s Almaden Research Center in San Jose, California packed 6.67 billion bits of data per square inch on magnetic tape developed with the help of Fuji Photo Film Company of Japan, IBM reported.

That was 15 times as much data as can fit on similar space on magnetic tapes considered the current industry standard, IBM spokesman Mike Ross says.

A cartridge half the size of a typical VHS tape cartridge used in home recorders will be able to hold the text from eight million books that would fill 92 kilometres of bookshelves, according to researchers. — AFP

Pregnancy & diabetes

Women with diabetes are less than half as likely as non-diabetic women to receive counselling on birth control from their doctors, a new study shows — despite the risk to the baby if a woman with diabetes conceives before optimal blood sugar control is achieved.

Dr Eleanor Bimla Schwarz of the University of Pittsburgh and her colleagues explain in the medical journal Obstetrics & Gynaecology that an unplanned pregnancy is a particular concern for diabetic women, who face twice the risk of having a child with a birth defect. But if blood sugar is under good control, Schwarz told Reuters Health, there’s a much better chance of having a problem-free pregnancy and delivery. — Reuters

Climate change may kill millions

Disease spread by global warming could kill an extra 185 million people in sub-Saharan Africa by the end of the century and turn millions more into refugees unless rich nations take action now, a report says.

Christian Aid said rich developed countries had to end their dependence on fossil fuels and set aside large sums of aid to help poorer nations ride out the worst impacts of global warming and switch to energy sources like wind, solar and waves.

‘’Rich countries must take responsibility for having largely created this problem — and cut CO2 emissions radically,’’ the non-governmental organisation said in a report ‘’The Climate of Poverty: facts, fears and hopes’’. — Reuters

HIV and human cells

Scientists have learned more details of the process which turns human cells into factories for viruses such as HIV.

It is known that viruses are able to hijack the genetic machinery of cells for their own ends.

Teams from Cambridge and Oxford Universities have witnessed the process in action, and have identified the crucial role of key elements. The study, published in Nature, may eventually lead to new treatments for HIV, and other infections.

Very many years of further research would be needed before this research finding will benefit HIV-positive patients. — ANI

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THIS UNIVERSE
PROF YASH PAL

If we drink coffee or tea after eating sweets, there is no sweetness left in these drinks. Why is it so?

Taste buds are receptors that fit in the molecules that give us a sensation of sweetness. After eating things that are very sweet, these receptors are saturated with such molecules; there are few seats that are vacant. Therefore, the signal of sweetness from things that are less sweet remains weak.

Why do we find tides at seashores, but not inside the sea? It is calm inside?

If you were sitting on a satellite, far out in space, and had an instrument to measure the distance to the sea level below you would find a bulge in the sea following the Moon. You would also see a bulge on the opposite side of the Moon. The level of the sea at right angle to the Earth-Moon line would be lower. This is what the whole tidal phenomenon is—primarily so, neglecting the effect of the Sun for the time being. The tidal force does not care how far you are from the coast. You are more aware of the rise and fall of water when you are near the coast because you have something to compare it with, namely the level of the coast. In the middle of the sea, all the water in the neighbourhood goes up and down and one is unaware of this gradual up and down motion twice a day.

If we expose any object to heat, it expands. The Earth is constantly exposed to the Sun’s heat. Is it expanding? If so, then by how much every year?

The Earth heats up during the day and cools down during the night. Because of our oceans and the atmosphere, the day and night temperatures do not go through such extremes as these would if the Earth were a dead planet, say like Mars or Mercury. The temperature change does produce some weathering and crumbling. But the temperature of the whole Earth does not change that much. This is because all the energy received from the Sun is not absorbed and retained. Some is scattered out into space by clouds and snow cover, and the heated Earth radiates the rest away to cold space. The equilibrium temperature of the Earth is reached when the energy radiated out combined with that scattered out by clouds, snow etc. is equal to the energy received from the Sun. (The energy radiated by a hot body is proportional to the fourth power its absolute temperature).

If you were to go a few meters below the ground, you would find that compared to the surface, you are not as hot during a summer day, or as cold during a winter night. Our Earth as a whole does not inflate or deflate significantly because its average temperature remains nearly constant. I must, however, qualify this statement. Consider the oceans. Temperature of the sea changes with seasons, but since the winter and summer hemispheres are connected, the average temperature is nearly constant.

Should there be a climate change, say due to global warming, and the average temperature of the sea increases by 5°C, something dramatic might happen. Volume of the sea would increase due to thermal expansion of water. If we assume that the spread of the oceans will remain about the same and also that the average depth of the ocean is 3 kilometres, increase in the height of the water would be about 3 meters. That could be very bad for coastal areas and small islands.

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