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Nanotechnology and nanomaterials New products & discoveries
UNDERSTANDING THE UNIVERSE |
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Nanotechnology and nanomaterials
NANOTECHNOLOGY is a new interdisciplinary subject, combining physics, engineering, chemistry and biology. It is so named because it deals with objects that are measured in nanometers. A nanometer (nm) is a billionth of a meter (10-9m). That is roughly the separation of two individuals (taken as points) of Chandigarh, if whole of its population is lined up on one-millimeter length. Atoms are the building blocks for all matter in our universe. Everything around us, including ourselves, is made of atoms. Nature is the best nanotechnology expert, it grows matter molecularly from cells. Cells being of nanodimensions, these are nature's nanomachines which build and replicate. The man-made products that we manufacture or buy are made by cutting or joining or pushing piles of atoms together in a bulky, imprecise manner. Manipulating individual atom of an object, and placing them in a pattern to produce a desired structure is the basic idea of nanotechnology. If that happens, almost everything, including medicine, computers and cars, can be designed and constructed differently. The products made from nanomachines will be materials with desirable properties such as high strength, chemical sensing or optical switching designed in from the start. Eventually, we will be able to replicate anything, including diamonds, water and food. Quantum computing will develop. Nanotechnology may have its biggest impact on the medical industry.
Patients will drink fluids containing nanorobots programmed to attack and reconstruct the molecular structure of cancer cells and viruses to make them harmless. Nanorobots could also be programmed to perform delicate surgeries. Nanotech-enabled military hardware — from the combat soldier to space-based nanobot arsenals — will make any current weapons of mass destruction seem as primitive as the sticks and stones used by low-tech primitive warriors. The subject of nanoscience has picked up during last decade or so, especially after so called fullerene molecules were discovered in 1985. Out of these, the ones having 60 carbon atoms also known as carbon C60 were found most interesting and abundant. The fullerene discovery also announced a third allotropic form of carbon, the two i.e. graphite and diamond being known to exist from centuries. The discovery of the C60 ball was important enough to be recognised for the 1996 Nobel Prize to Robert F. Curl, Harold W. Kroto and Richard E. Smalley. As a consequence of fullerene research, carbon nanotubes emerged. These systems consist of graphitic sheets seamlessly wrapped to cylinders. With only a few nano-meters in diameter, yet grown up to a millimeter length, the length-to-width aspect ratio is extremely high. At Physics Department in Panjab University, the subject of fullerene and nanotube materials has been one of the areas of research activity since last decade. In view of the significance attached to the subject of nanotechnology, there is need for an interdisciplinary course involving young faculty from amongst physicists, chemists, biologists, and engineering branches to provide manpower input for industry and research. The course should aim at preparing students for nanotechnology by providing them with a sound grounding in multi-disciplinary areas of nanoscience at such centre of nanotechnology and new materials. The course should prepare graduates/post graduates who, while skilled in areas of nanoscience, will be qualified for jobs in traditional science. As the nanotechnologies merge and mature, they will be positioned for jobs in this applied area also in industry and government labs. The course should be designed to enable the students to develop a range of professional, scientific and computational skills that will enhance employment opportunities. The writer is
Professor of Physics, Panjab University, Chandigarh. His group is
involved in carbon nanotubes and fullerene research at PU |
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New products & discoveries
RESEARCHERS have developed and field-tested a new technique that identifies specific soil microbes that can break down environmental pollutants. The bacteria could be used to clean up toxic-waste sites. Eugene Madsen of Cornell University and his colleagues tested their technique at a coal tar waste site associated with an old gasworks.The researchers labelled a test sample of naphthalene-a common, seemingly benign coal tar component-with the isotope carbon-13 and released the chemical into the soil. The researchers then covered patches of soil with 250-millilitre glass jars. If a plot harboured soil bacteria capable of metabolising the naphthalene, carbon dioxide that included carbon-13 built up in the jar over that soil. Because these bacteria also incorporate carbon-13 into their DNA, Madsen and his coworkers could identify a specific strain of naphthalene-degrading bacteria. Meteor caused "Great Dying" The "Great Dying," a time of earth’s greatest number of extinctions, appears to have been caused by the impact of a large meteor, according to a research team that includes Luann Becker, a scientist with the Institute for Crustal Studies in the Department of Geology at the University of California, Santa Barbara. The theory, recently published by the team in the journal Science (Nov. 21, 2003), explains that this extinction event, which occurred approximately 251 million years ago, is much earlier than the demise of the dinosaurs, which is estimated at approximately 65 million years ago and is also believed to have been caused by a large meteor impact. The evidence is the most convincing yet for an impact at the "end-Permian," a time commonly referred to as "The Great Dying," when life was nearly erased from the earth, explained Becker. She is currently working in Antarctica with a team searching for more "impact tracers," the geological markers that show evidence of large meteors hitting the earth. Rock-eating microbes! Geologists are studying
bacteria nowadays. It’s not that the rock hounds have gone soft.
Instead, they’ve found that geological processes once attributed
solely to simple inorganic chemistry have microbial fingerprints all
over them. In rocky venues ranging from abandoned mines in California
to water wells in Bangladesh to hydrothermal vents on the seafloor,
bacteria are at work. If the microbes aren’t driving the underlying
chemical reactions in those places, they’re at least taking
advantage of the energy that’s being released by these reactions. |
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UNDERSTANDING THE UNIVERSE Why doesn’t the female immune system reject the male sperm? Good question. It is a fact that if sperms are injected into the muscle or skin of a woman (and in fact, men as well) like conventional vaccines are, they generate a potent immune response. This tells us that, in this context, the immune system is perfectly capable of recognising sperm as "foreign". Why then, in the normal course of events, is there no deleterious immune response to sperms after sexual intercourse? The seminal fluid, in which sperms are suspended, contains potent proteins known as cytokines, as well as other bio-molecules, which strongly dampen the influence of the maternal immune system. The special microenvironment of the female reproductive tract may also be partially responsible for the lack of response. When normal control mechanisms break down, anti-sperm antibodies do result; this breakdown is often associated with infertility. It is to be recognised that without such cleverly designed exceptions propagation of life would have been impossible. There is another fact of procreation that is worth noting. The blood group of the mother and the foetus in her womb need not be the same. In such a case mother’s blood could be poisonous for the baby, but it is not because it is not allowed to mix with that of the unborn baby. The porous membranes allow nutrition to be transferred to the baby but not the blood. Many wondrous mechanisms have been invented through evolution - their sophistication and reliability should give some humility to all cocky technologists. How does the paper cone in a loudspeaker produce different types of sound? The circumference of the paper cone is usually fixed on a frame, while the central part is connected to a coil that is free to move but is inductively coupled to another coil. Changes of current in that coil represent the vibrations of sound recorded on tape, or any other medium, or coming from microphone. This way the paper cone is made to vibrate with the frequency and volume of the sound. Basically the paper cone speaker is a mechanism for converting the electrical vibrations of the system back into mechanical vibrations we call sound. Electromagnetic coupling of the cone might be somewhat different from the one I have mentioned but some such coupling is clearly required. Which species would survive a nuclear war and why? Frankly I do not know. I think if there were a full-scale nuclear war in which all the stored nuclear bombs were used, I would prefer to be amongst those who do not survive. Those who die quickly would be the lucky ones. After effects of such a war would be horrible. If humans let lose such an abomination on the planet then they deserve to be wiped out. Speaking academically, it is
possible that those species might survive that live in dark holes, demanding
very little infrastructure. Some people think cockroaches might have a good
chance. |
