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| SCIENCE & TECHNOLOGY |
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Plastic from plants Phone chip that counters radiation Dogs have sense of fairness
Story of uranium |
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Plastic from plants However, the same feature that makes plastics so versatile, also presents a major concern. One of the most pressing environmental problems is that of the constantly growing mountain of waste. Plastic is a material made up of one or more polymers. Presently, the main source of the chemicals needed to manufacture plastics is fossil fuels. Rising concern about the cost of fossil fuels, and their impact on the environment has resulted in a search for alternatives to petrochemical plastics, namely biopolymers and bioplastics. Bioplastics are plastics manufactured using biopolymers, and are biodegradable. Biopolymers and bioplastics are often referred to as bio-based plastics and polymers, or as biodegradable plastics or polymers. Biopolymers are polymers which are present in, or created by, living organisms. These include polymers from renewable resources that can be polymerised to create bioplastics. Biopolymers and bioplastics are not new products. Henry Ford developed a method of manufacturing plastic car parts from soybeans in the mid-1900s. However, World War II side-tracked the production of bioplastic cars. Today, bioplastics are gaining popularity once again as new manufacturing techniques developed through biotechnology are being applied to their production. Bioplastics are a form of plastics derived from plant sources such as hemp oil, soy bean oil and corn starch rather than traditional plastics which are derived from petroleum. This is regarded as a much more sustainable activity, as it relies considerably less on fossil fuel imports and produces less greenhouse emissions, producing between 0.8 and 3.2 tonnes of carbon dioxide less per tonne of bioplastics compared to the same weight in petroleum-based plastics. Many bioplastics are truly biodegradable and will degrade in commercial composting units. Some bioplastics will even biodegrade in the less aggressive conditions of a home compost heap. However, bioplastics can also be formulated to be durable. There is a need to promote plastics that are biodegradable, compostable and based on renewable resources which is set to represent the industry and provide a streamlined view on issues relating to the benefits of bioplastics. In many areas, the technology is still relatively new and currently not as cost competitive with petroleum-based plastics, although that is quickly changing. However, bioplastics are already seeing some use in Europe. The most common end use market is for packaging materials. Japan has also been a pioneer in bioplastics, incorporating them into electronics and automobiles. There are two methods being researched and used to produce plastics from plants. The first uses fermentation, and the second relies on the plant to become the factory for plastic production. Fermentation, used for hundreds of years by humans, is even more powerful when coupled with new biotechnology techniques. Fermentation is the use of microorganisms to break down organic substances in the absence of oxygen. Today, fermentation can be carried out with genetically engineered microorganisms, specially designed for the conditions under which fermentation takes place, and for the specific substance that is being broken down by the microorganism. There are two ways fermentation can be used to create biopolymers and bioplastics. Bacterial Polyester Fermentation – Bacteria are one group of microorganisms that can be used in the fermentation process. Fermentation, in fact, is the process by which bacteria can be used to create polyesters. The bacteria use the sugar of harvested plants, such as corn, to fuel their cellular processes. The by-product of these cellular processes is the polymer. The polymers are then separated from the bacterial cells. Lactic Acid Fermentation – Lactic acid is fermented from sugar, much like the process used to directly manufacture polymers by bacteria. However, in this fermentation process, the final product of fermentation is lactic acid, rather than a polymer. After the lactic acid is produced, it is converted to polylactic acid using traditional polymerization processes. Also, genetic engineering can be used to create plants, such as soybean, specifically designed to be used as a raw material for the production of bioplastics. Thus, plants are becoming factories for the production of plastics. Researchers have already created a Arabidopis thaliana plant through genetic engineering which contains the enzymes used by bacteria to create plastics. Bacteria create the plastic through the conversion of sunlight into energy. The researchers have transferred the gene that codes for this enzyme into the plant; as a result the plant produces plastic through its cellular processes. The plant is harvested and the plastic is extracted from it using a solvent. The liquid resulting from this process is distilled to separate the solvent from the plastic. That is why researchers have been attempting to genetically engineer plants to act as mini plastic factories. Improving efficiency is a major concern for the production of bioplastics. Currently, fossil fuel is still used as an energy source during the production process. This has raised questions by some regarding how much fossil fuel is actually saved by manufacturing bioplastics. Only a few processes have emerged that actually use less energy in the production process. Therefore, researchers are still working on refining the processes used in order to make bioplastics viable alternatives to petrochemical plastics. There are also concerns about how to balance the need to grow plants for food, and the need to grow plants for use as raw materials. Agricultural space needs to be shared so researchers are looking into creating a plant that can be used for food, but also as feedstock for plastic production. Eventually, they are hoping to create the plant in a way which would restrict the plastic production to the stem, and leaves of the plant. This would leave the edible part of the plant plastic free which could be used as food, or as livestock feed and removing plastic from the remaining part of the plant. Such project of bioplastics from plants will create new technology and jobs, expand opportunities for bio-based industries and agricultural suppliers, decrease our dependence on oil, strengthen the agricultural economy, provide new markets for farmers and marry new agricultural product development with sophisticated manufacturing skills and the knowledge to commercialize these projects. Need is to look at adding other low-cost agricultural ingredients to develop bioplastics. The writer is from Department of Physics, S.L.I.E.T., Longowal |
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Phone chip that counters radiation BELGIAN health products distributor Omega Pharma will launch a chip it claims can counter potentially damaging radiation from mobile phones and has high hopes for its sales. The company, which sells non-prescription products such as wart treatments, pregnancy tests and suntan lotions to pharmacists, unveiled the E-waves phone chip on Tuesday, a day before its launch in Belgium. Testing of the chip, which offsets the electromagnetic radiation from the phone, showed it lessened symptoms such as headaches and loss of concentration that might be associated with mobile phone use, Omega said. It also neutralised the heating effect within the body produced by electromagnetic signals. Testing of consumers appetite for the product, costing 38.95 euros ($50.1), will start on Wednesday. The company will only have 30,000 of the chips available on day one, but believes it can ramp up production easily for foreign expansion. “If we need 10 million, then we’ll go for that,” Chief Executive Marc Coucke told Reuters on the sidelines of the launch, although he said that was not a forecast. Coucke and the scientists who have developed the chip argue there is a growing body of evidence showing a link between mobile phone use and the growth of tumours. “It’s like smoking. Eventually we reached a point where the health impact is widely acknowledged,” Coucke said. However, scientists worldwide remain split between those that believe there is a risk and others who believe there is insufficient evidence to show mobile phones are unsafe. Omega, which has exclusive international distribution rights, will begin selling the product in other countries from early 2009. It will also launch three similar devices designed for use in the car, linked to a computer and in the home. Omega competes with the over-the-counter arms of pharma giants such as Johnson & Johnson and Bayer and of consumer products groups such as Procter & Gamble. Omega, the only sizeable stand-alone OTC company, ranks itself 11th in the world in that
market. — Reuters |
NOT fair! What parent hasn’t heard that from a child who thinks another youngster got more of something? Well, it turns out dogs can react the same way. Ask them to do a trick and they’ll give it a try. For a reward, sausage say, they’ll happily keep at it. But if one dog gets no reward, and then sees another get sausage for doing the same trick, just try to get the first one to do it again. Indeed, he may even turn away and refuse to look at you. Dogs, like people and monkeys, seem to have a sense of fairness. “Animals react to inequity,” said Friederike Range of the University of Vienna, Austria, who led a team of researchers testing animals at the school’s Clever Dog Lab. “To avoid stress, we should try to avoid treating them differently.” Similar responses have been seen in monkeys. Range said she wasn’t surprised at the dogs’ reaction, since wolves are known to cooperate with one another and appear to be sensitive to each other. Modern dogs are descended from wolves. Next, she said, will be experiments to test how dogs and wolves work together. “Among other questions, we will investigate how differences in emotions influence cooperative abilities,” she said via e-mail. In the reward experiments reported in Tuesday’s edition of Proceedings of the National Academy of Sciences, Range and colleagues experimented with dogs that understood the command “paw,” to place their paw in the hand of a researcher. It’s the same game as teaching a dog to “shake hands.” Those that refused at the start - and one border collie that insisted on trying to herd other dogs - were removed. That left 29 dogs to be tested in varying pairs. The dogs sat side-by-side with an experimenter in front of them. In front of the experimenter was a divided food bowl with pieces of sausage on one side and brown bread on the other. The dogs were asked to shake hands and each could see what reward the other received. When one dog got a reward and the other didn’t, the unrewarded animal stopped playing. When both got a reward all was well. One thing that did surprise the researchers was that - unlike primates - the dogs didn’t seem to care whether the reward was sausage or bread. Possibly, they suggested, the presence of a reward was so important it obscured any preference. Other possibilities, they said, are that daily training with their owners overrides a preference, or that the social condition of working next to a partner increased their motivation regardless of which reward they got. And the dogs never rejected the food, something that primates had done when they thought the reward was unfair. The dogs, the researchers said, “were not willing to pay a cost by rejecting unfair offers.”
— AP |
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Story of uranium AT the tender age of 15 years, Martin Klaproth dropped out of school. He could not pay his fees. He learnt chemistry from the work benches as an apprentice under an apothecary. He struggled for long hours "in the cramped and unhealthy conditions and the tedium of preparing the raw materials and maintaining the hardware for the crushing, grinding, mixing, boiling and distilling that made up his daily routine". Later, Martin opened his own business. He could spend more time to do research in analytical chemistry. He analysed all types of materials from various countries. He extracted a new element from a piece of rock, some mine-owner gave him. He called it uranium. He announced the discovery at a meeting of the Royal Prussian Academy of Sciences, Berlin, on September 24, 1789. Uranium remained virtually useless for several decades; small amounts of uranium added to glass before melting gave the glass a pale-yellowish green hue. Some glass specimens contained up to 25 per cent uranium! Geiger counters screamed when it faced the glass surface. In 1896, Henri Becquerel discovered that uranium is radioactive .In 1934, Enrico Fermi and his coworkers demonstrated beta activity when they bombarded uranium with neutrons. In 1938, Otto Hahn and Leise Meitner discovered nuclear fission and release of fission neutrons. On December 2, 1942, Fermi and his team achieved the first self-sustaining nuclear chain reaction in a pile of 400 tons of graphite, six tons of uranium metal and 58 tons of uranium oxide, at the University of Chicago. It produced 0.5 watt of thermal power! Scientists realised the full potential of uranium when they could design, construct and operate nuclear power reactors 168 years after Klaproth discovered it. India's tryst with uranium started in 1937 when an English man discovered its presence with copper mineral at Mosabani area. There was apparently no followup on this till late 40s. Dr Homi Bhabha, the architect of nuclear India, knew the value of uranium. "It must be clearly understood that the possession of sufficient quantities of uranium is a sine qua non for the generation of atomic energy….. So far, no large and concentrated deposits of uranium-bearing minerals have been found in India,……It is essential, therefore, that our immediate programme should include an extensive and intense search for sources of uranium. These geological surveys would take at least two years if carried out in any careful and exhaustive way, and it is possible that their result may be negative. In that case India would either have to depend on an agreement with a foreign power for the purchase of her uranium or go in for the much more costly process of extracting uranium from monazite", Dr Bhabha wrote to Pandit Nehru on April 26, 1948. Dr Bhabha informed Nehru that the Geological Survey of India under Dr. M.S.Krishnan was organizing surveys for thorium and uranium. He insisted that to ensure secrecy, these surveys should be organised directly under the Atomic Energy Commission and Dr. Krishnan "should be allocated full time to this work" According to Dr K.S. Koppiker, formerly Head, Uranium and Rare Earth Division, BARC, Indian scientists set up in 1949, the first uranium laboratory in Pedder road, Mumbai, at the residence of Dr Bhabha, where Kenilworth building stands today. Their neighbours complained that they could not suffer the unbearable releases of acid fumes from the laboratory. In July 1954, scientists shifted the lab to an abandoned godown owned by the Bombay Dyeing Company near Siddhi Vinayak Temple. Uranium is present in trace quantities in soil, rock, water etc. Typical concentration in soil is about 3 ppm (milligramme per kilo gramme). (K.S. Parthasarathy is Raja Ramanna Fellow, Department of Atomic Energy)
Prof Yash Pal’s column has not been received this week. It will appear in the next issue.
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WE all know that due to excellent thermal and mechanical properties, good suitability at dampening noises and vibrations, good at returning to their original shapes with the application of heat and also possessing electrical and magnetic properties plastics are becoming very popular. Plastics have helped to shape the world around us. They are incorporated into everything from heart valves to baby bottles and are virtually indestructible.