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Age of Grid: Download at the blink of eye Prof Yash
Pal This
Universe |
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PGI’s kidney research appreciated in US Flexible circuits
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Age of Grid: Download at the blink of eye This would be like taking 10,000 quantum steps at the click of a mouse! The Grid, which was launched in 2002, will connect thousands of computers to assess the data generated by experiments in the Large Hadron Collider (LHC). According to the CERN, the data produced by the LHC each year would be enough to write a pile of CDs 20 km long. LHC is a machine which would enable two beams of protons or Lead ions to collide at a striking spead of 99.9 per cent of the speed of light, i.e 29,97,00,000 m/sec. All these big numbers would help in deeper understanding of the universe. Scientists would have been facing lot of difficulties in storing such a huge data and also power to run computers. It is almost impossible with the current computer technology. The Grid tries to tackle this problem by unifying computers all over the world as one single, huge and powerful computer. It is actually software that enables the user to access computers distributed over a network. It is also called ‘middleware’ which connects operating softwares with the application ones. There exist programmes, which use widely distributed computers on a network like SETI@home, which runs over 500,000 PCs worldwide to analyse signals for extra-terrestrial life. But CERN says, the SETI@home runs on idle private PCs, whereas the Grid uses dedicated resources in major computer centres and can thus handle problems of far greater complexity. It will get operational as soon as the LHC is switched on. The first users of this technology other than particle physicists could be biologists and earth scientists, who have to deal with the massive data. For example, to unlock the secrets of human genome, sequencing of three billion chemical units that comprise DNA is required. And the domestic users would be downloading movies in a fraction of seconds, and chatting, mailing, uploading at the same second, may be in few years. |
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Universe Why does a piece of chalk (which is not a perfect cylinder) exhibit motion on a curved path? I imagine that moment of inertia and the offset centre of gravity play a role in the torque formation. I would appreciate a detailed physical and mathematical explanation. I understand your question in the following way. When you place a chalk stick horizontally on a slightly tilted plane, you find that it does not roll straight down but describes a curved path. If I am correct in this interpretation of your question, the answer could be the following: The force on the horizontal chalk stick is that due to gravity, of which the component normal to the surface of the plane is cancelled by the reaction of the plane, while the component parallel to surface wants to drag the chalk stick downwards along the surface. If the frictional force were small, the chalk stick would just slide down horizontally. This could be checked by using an oiled steel surface or, for that matter, a glass surface. But for a chalk stick on a normal dry surface, the friction is high and the tendency to slip immediately produces a rolling motion, for which the friction is negligible. When the chalk stick is rolling then, for each rotation, the thicker end of the chalk will travel a greater distance than the thinner end and this will automatically produce a curved path. Because of angular momentum, the stick will go a little beyond the vertical and then swing back to a vertical position. It will then become stationery unless the tilt of the surface is increased, in which case it will slide vertically down. |
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PGI’s kidney research appreciated in US Every other day we hear appeals in the papers of appeals of patients suffering from kidney diseases. The cases are on the rise, and it is heartening to know that research work done in Chandigarh’s PGI has been greatly appreciated in a US medical journal.
It was a great day for Dr. C.S. Rayat and his colleagues from the PGI, when they heard that their research paper has been published in Analytical and Quantitative Cytology and Histology (Glomerular morphometry in biopsy evaluation of minimal change disease, membranous glomerulonephritis, thin basement membrane disease and Alport’s syndrome.) An exclusive report from the same was prepared and published by Gastroenterology Week under the heading “Alport’s Syndrome: Reports from Postgraduate Institute of Medical Education and Research add new data to research in membranous glomerulonephritis”. According to Dr Rayat, who has over a dozen acclaimed papers to his credit, there are a variety of kidney (renal) diseases. Swelling of face, excretion of protein and/or red blood cells in urine are preliminary indications of renal disease, and its associated ailments may be varied. For a histopathological evaluation, kidney biopsy (a small piece of kidney) is taken by the nephrologists and submitted for histopathological diagnosis. When we look at microchips of the kidney biopsy with a light microscope that is called microscopic examination and the examination of ultra-thin chips of the kidney biopsy with electron microscope is called ultrastructural examination. The department of histopathology at PGI Chandigarh is equipped with state-of-the-art equipment for histopathological diagnosis of renal biopsies. Microscopic and ultrastructural findings could be descriptive as well as quantitative. The quantitative findings of the renal glomerulus are called glomerular morphometric findings which were extensively evaluated in the above cited research paper. Kidneys are excretory as well as regulatory organs of our body and there are about one million functional components called nephrons in each kidney. Glomerulus is the part of each nephron where blood is filtered through a semi-permeable membrane called glomerular basement membrane (GBM). Glomerular filtrate is further processed in urinary tubules to excrete out urine. The lobules of the glomerular tuft are composed of wreaths of capillaries surrounding a central stalk or mesangium. The lumen of each capillary is separated from the urinary space by the GBM. The microscopic picture of kidney is far from simple as may be gathered from the wide variety of interpretations which has been applied to it. The cited study was conducted in four renal disorders to ascertain the quantitative changes internal to glomeruli with a focus on diagnostic implications in renal disorders. Dr Rayat and his colleagues have found that the role of electron microscopy is implicit in achieving a diagnosis of thin basement membrane disease where GBM is found to be less than 265 nano metres thick in adults. Glomeruli in patients of Alport’s Syndrome showed irregular thickening and splitting of GBM at ultrastructural level and variable but conclusive changes at morphometric level which could be used as an adjunct to the descriptive diagnostic features in these cases. The glomerular morphometric study revealed significant increase in glomerular “diameter and area” and “tuft diameter and area” in addition to drastic changes in intra-glomerular compartments in patients of idiopathic membranous glomerulonephritis. The knowledge gained from the study is being utilised for diagnostic interpretations of kidney biopsies at PGI, Chandigarh and many international researchers and pathologists have been appreciating the study.
— TNS |
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Flexible circuits Electronics is ruling the civilisation at present and many efforts are being made to make this technology more suitable and adoptable to the users. Electronics circuits till now are used to be fabricated on rigid/hard substrates and this rigidity imposes shape limitations for electronic equipments. Though miniaturisation of integrated circuits has helped to a large extent in giving the desired shape to electronic equipments but still this can be more exploited with the latest developments in the fabrication of flexible circuits. Flexible circuitry reduces the size and weight of a finished product. It allows increased circuit density and eliminates bulky connections and wiring. And the added ability to fold the circuit expands the boundaries of design and packaging. Flexible electronics, also known as flex circuits or flex circuit boards, is a technology for assembling electronic circuits by mounting electronic devices on flexible high-performance plastic substrates, such as polyimide. Circuits can be designed in configurations from simple, single-sided conductive paths to complex high density three-dimensional assemblies utilising a variety of fabrication materials from low cost polyester to mid range PEN to high density adhesiveless polyimide Novaclad. Additionally, flex circuits can be screen printed silver circuits on polyester. Flexible electronic assemblies may be manufactured using identical components used for rigid printed circuit boards, allowing the board to conform to a desired shape, or to flex during its use. The original recipe for flexible CMOS circuits comprised a 2- to 3-micrometre circuit layer sitting atop a plastic substrate as much as 100 µm thick. It could curve around a small roll of coins. But the new version has a total thickness of only 1.7 µm, including the plastic, which gives it the ability to wrap around a rod whose diameter is roughly 85 µm. In LCD fabrication, glass is used as a substrate. If thin flexible plastic or metal foil is used as the substrate instead, the entire system can be flexible, as the film deposited on top of the substrate is usually very thin, on the order of a few micrometres. OLEDs are normally used instead of a back-light for flexible displays, making a flexible organic light-emitting diode display. Flexible solar cells have been developed for powering satellites. These cells are lightweight, can be rolled up for launch, and are easily deployable, making them a good match for the application. The development of bendable, twistable electronic circuits has been reported whose performance nearly matches that of conventional CMOS chips. The new circuits, developed by a team of researchers at the University of Illinois at Urbana-Champaign (USA) are built from ribbons of silicon only a few nanometers thick that are mounted on flexible plastic substrates. Same group or researchers has developed an improved plastic circuit that is not only flexible but also stretchable and foldable. To make it foldable, the researchers looked at the behavior of everyday objects so they decided to make the circuit much thinner. Researchers at the University of Illinois at Urbana-Champaign (USA) make plastic circuits by transferring thin ribbons of silicon onto glue-coated plastic using a patterned rubber stamp. But before the ultrathin silicon layer is applied to the substrate, the plastic is heated, causing it to expand. Once the circuit layer is deposited and chemically bonded to the expanded substrate, the plastic is allowed to cool and contract. Relaxing the strain causes the circuit layer to buckle and form wavy patterns like the bellows of an accordion. It’s the folds and wrinkles that give the circuit the ability to stretch and bend without breaking. Researchers say that in laboratory tests, the circuits, after a few hundred stretch-and-release cycles, showed no signs of fatigue. Flex circuits are often used as connectors in various applications where flexibility, space savings, or production constraints limit the serviceability of rigid circuit boards or hand wiring. In addition to cameras, a common application of flex circuits is in computer keyboard manufacturing; most keyboards made today use flex circuits for the switch matrix. Flexible circuit offers value added services that will help with bringing the design to reality with following advantages:
The writer is from Department of Physics, S.L.I.E.T., Longowal, |
