Flank wear is due to the abrasive action of hard mis-constituents including debris from built up edge as the work material rubs the work surface. ?->(Show Answer!)

1. Flank wear is due to the abrasive action of hard mis-constituents including debris from built up edge as the work material rubs the work surface.

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MCQ->Flank wear is due to the abrasive action of hard mis-constituents including debris from built up edge as the work material rubs the work surface.....

MCQ-> Read the following passage and answer the questions. Passage: A new paper published by Rochman and her colleagues in February, in the journal Ecology, sifts through past research on marine debris to assess the true extent of the environmental threat. Plenty of studies have sounded alarm bells about the state of marine debris: Rochman and her colleagues set out to determine how many of those perceived risks are real Often. Rochman says, scientists will wrap up a paper by speculating about the broader impacts of what they've found. Maybe their study has shown that certain seabirds eat plastic bags, for example, and the paper goes on to warn that whole bird populations are at risk of dying out. "But the truth was that nobody had yet tested those perceived threats." Rochman says. "There wasn't a lot of information." Rochman and her colleagues examined more than a hundred papers on the impacts of marine debris that were published through 2013. Within each paper. they asked what threats scientists had studied-366 perceived threats in all and what they'd actually found. In 83 percent of cases, the perceived dangers of ocean trash were proven true. In most of the remaining cases. the working group found the studies too shoddy to draw conclusions from—they lacked a control group, for example. or used faulty statistics. Strikingly. Rochman says, only one well-designed study failed to find the effect it was looking for, an investigation of mussels ingesting microscopic plastic bits. The plastic moved from the mussels' stomachs to their bloodstreams. scientists found. and stayed there for weeks—but didn't seem to stress out the shellfish. A lot of ocean debris is "microplastic," or pieces smaller than five millimetres. These may be the beads from a facial scrub. fibres shed by synthetic clothing in the wash. or eroded remnants of larger debris. Compared to the number of studies investigating large-scale debris. Roclunan's group found little research on the effects of these tiny bits. There are also, she adds, a lot of open questions about the ways that ocean debris can lead to sea-creature death. Many studies have looked at how plastic affects an individual animal or that animal's tissues or cells, rather than whole populations. And in the lab, scientists often use higher concentrations of plastic than what's really in the ocean. None of that tells us how many birds or fish or sea turtles could die form plastic pollution or how deaths in one species could affect that animal's predators, or the rest of the ecosystem. "We need to be asking more ecologically relevant questions." Rothman says. Usually, scientists don't know how disasters like oil spills or nuclear meltdowns will affect the environment until after they've happened. she says. "We don't ask the right questions early enough." But if ecologists can understand how the slow-moving disaster of ocean garbage is affecting ecosystems. they might be able to prevent things from getting worse.Which ONE of the following conclusions based on the examination of the hundred-odd papers on marine debris and its ecological impact by Rachman and her colleagues is NOT CORRECT?
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MCQ->If two of them wear the same colour, then how many of the following must be false? I. Amar wears blue and Akbar does not wear green II. Amar does not wear blue and Akbar wears blue III. Amar does not wear blue and Akbar does not wear blue IV. Amar wears green, Akbar does not wear red, Anthony does not wear green....

MCQ-> In a modern computer, electronic and magnetic storage technologies play complementary roles. Electronic memory chips are fast but volatile (their contents are lost when the computer is unplugged). Magnetic tapes and hard disks are slower, but have the advantage that they are non-volatile, so that they can be used to store software and documents even when the power is off.In laboratories around the world, however, researchers are hoping to achieve the best of both worlds. They are trying to build magnetic memory chips that could be used in place of today’s electronics. These magnetic memories would be nonvolatile; but they would also he faster, would consume less power, and would be able to stand up to hazardous environments more easily. Such chips would have obvious applications in storage cards for digital cameras and music- players; they would enable handheld and laptop computers to boot up more quickly and to operate for longer; they would allow desktop computers to run faster; they would doubtless have military and space-faring advantages too. But although the theory behind them looks solid, there are tricky practical problems and need to be overcome.Two different approaches, based on different magnetic phenomena, are being pursued. The first, being investigated by Gary Prinz and his colleagues at the Naval Research Laboratory (NRL) in Washington, D.c), exploits the fact that the electrical resistance of some materials changes in the presence of magnetic field— a phenomenon known as magneto- resistance. For some multi-layered materials this effect is particularly powerful and is, accordingly, called “giant” magneto-resistance (GMR). Since 1997, the exploitation of GMR has made cheap multi-gigabyte hard disks commonplace. The magnetic orientations of the magnetised spots on the surface of a spinning disk are detected by measuring the changes they induce in the resistance of a tiny sensor. This technique is so sensitive that it means the spots can be made smaller and packed closer together than was previously possible, thus increasing the capacity and reducing the size and cost of a disk drive. Dr. Prinz and his colleagues are now exploiting the same phenomenon on the surface of memory chips, rather spinning disks. In a conventional memory chip, each binary digit (bit) of data is represented using a capacitor-reservoir of electrical charge that is either empty or fill -to represent a zero or a one. In the NRL’s magnetic design, by contrast, each bit is stored in a magnetic element in the form of a vertical pillar of magnetisable material. A matrix of wires passing above and below the elements allows each to be magnetised, either clockwise or anti-clockwise, to represent zero or one. Another set of wires allows current to pass through any particular element. By measuring an element’s resistance you can determine its magnetic orientation, and hence whether it is storing a zero or a one. Since the elements retain their magnetic orientation even when the power is off, the result is non-volatile memory. Unlike the elements of an electronic memory, a magnetic memory’s elements are not easily disrupted by radiation. And compared with electronic memories, whose capacitors need constant topping up, magnetic memories are simpler and consume less power. The NRL researchers plan to commercialise their device through a company called Non-V olatile Electronics, which recently began work on the necessary processing and fabrication techniques. But it will be some years before the first chips roll off the production line.Most attention in the field in focused on an alternative approach based on magnetic tunnel-junctions (MTJs), which are being investigated by researchers at chipmakers such as IBM, Motorola, Siemens and Hewlett-Packard. IBM’s research team, led by Stuart Parkin, has already created a 500-element working prototype that operates at 20 times the speed of conventional memory chips and consumes 1% of the power. Each element consists of a sandwich of two layers of magnetisable material separated by a barrier of aluminium oxide just four or five atoms thick. The polarisation of lower magnetisable layer is fixed in one direction, but that of the upper layer can be set (again, by passing a current through a matrix of control wires) either to the left or to the right, to store a zero or a one. The polarisations of the two layers are then either the same or opposite directions.Although the aluminum-oxide barrier is an electrical insulator, it is so thin that electrons are able to jump across it via a quantum-mechanical effect called tunnelling. It turns out that such tunnelling is easier when the two magnetic layers are polarised in the same direction than when they are polarised in opposite directions. So, by measuring the current that flows through the sandwich, it is possible to determine the alignment of the topmost layer, and hence whether it is storing a zero or a one.To build a full-scale memory chip based on MTJs is, however, no easy matter. According to Paulo Freitas, an expert on chip manufacturing at the Technical University of Lisbon, magnetic memory elements will have to become far smaller and more reliable than current prototypes if they are to compete with electronic memory. At the same time, they will have to be sensitive enough to respond when the appropriate wires in the control matrix are switched on, but not so sensitive that they respond when a neighbouring elements is changed. Despite these difficulties, the general consensus is that MTJs are the more promising ideas. Dr. Parkin says his group evaluated the GMR approach and decided not to pursue it, despite the fact that IBM pioneered GMR in hard disks. Dr. Prinz, however, contends that his plan will eventually offer higher storage densities and lower production costs.Not content with shaking up the multi-billion-dollar market for computer memory, some researchers have even more ambitious plans for magnetic computing. In a paper published last month in Science, Russell Cowburn and Mark Well and of Cambridge University outlined research that could form the basis of a magnetic microprocessor — a chip capable of manipulating (rather than merely storing) information magnetically. In place of conducting wires, a magnetic processor would have rows of magnetic dots, each of which could be polarised in one of two directions. Individual bits of information would travel down the rows as magnetic pulses, changing the orientation of the dots as they went. Dr. Cowbum and Dr. Welland have demonstrated how a logic gate (the basic element of a microprocessor) could work in such a scheme. In their experiment, they fed a signal in at one end of the chain of dots and used a second signal to control whether it propagated along the chain.It is, admittedly, a long way from a single logic gate to a full microprocessor, but this was true also when the transistor was first invented. Dr. Cowburn, who is now searching for backers to help commercialise the technology, says he believes it will be at least ten years before the first magnetic microprocessor is constructed. But other researchers in the field agree that such a chip, is the next logical step. Dr. Prinz says that once magnetic memory is sorted out “the target is to go after the logic circuits.” Whether all-magnetic computers will ever be able to compete with other contenders that are jostling to knock electronics off its perch — such as optical, biological and quantum computing — remains to be seen. Dr. Cowburn suggests that the future lies with hybrid machines that use different technologies. But computing with magnetism evidently has an attraction all its own.In developing magnetic memory chips to replace the electronic ones, two alternative research paths are being pursued. These are approaches based on:
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MCQ-> Read the following passage carefully and answer the questions given below it. Certain words/phrases have been printed in bold to help you locate them while answering some of the questions. The past quarter of a century has seen several bursts of selling by the world’s governments, mostly but not always in benign market conditions. Those in the OECD, a rich-country club, divested plenty of stuff in the 20 years before the global financial crisis. The first privatisation wave, which built up from the mid-1980s and peaked in 2000, was largely European. The drive to cut state intervention under Margaret Thatcher in Britain soon spread to the continent. The movement gathered pace after 1991, when eastern Europe put thousands of rusting state-owned enterprises (SOEs) on the block. A second wave came in the mid-2000s, as European economies sought to cash in on buoyant markets. But activity in OECD countries slowed sharply as the financial crisis began. In fact, it reversed. Bailouts of failing banks and companies have contributed to a dramatic increase in government purchases of corporate equity during the past five years. A more lasting fea ture is the expansion of the state capitalism practised by China and other emerging economic powers. Governments have actually bought more equity than they have sold in most years since 2007, though sales far exceeded purchases in 2013. Today privatisation is once again “alive and well”, says William Megginson of the Michael Price College of Business at the University of Oklahoma. According to a global tally he recently completed, 2012 was the third-best year ever, and preliminary evidence suggests that 2013 may have been better. However, the geography of sell-offs has changed, with emerging markets now to the fore. China, for instance, has been selling minority stakes in banking, energy, engineering and broadcasting; Brazil is selling airports to help finance a $20 billion investment programme. Eleven of the 20 largest IPOs between 2005 and 2013 were sales of minority stakes by SOEs, mostly in developing countries. By contrast, state-owned assets are now “the forgotten side of the balance-sheet” in many advanced economies, says Dag Detter, managing partner of Whetstone Solutions, an adviser to governments on asset restructuring. They shouldn’t be. Governments of OECD countries still oversee vast piles of assets, from banks and utilities to buildings, land and the riches beneath (see table). Selling some of these holdings could work wonders: reduce debt, finance infrastructure, boost economic efficiency. But governments often barely grasp the value locked up in them. The picture is clearest for companies or company-like entities held by central governments. According to data compiled by the OECD and published on its website, its 34 member countries had 2,111 fully or majority-owned SOEs, with 5.9m employees, at the end of 2012. Their combined value (allowing for some but not all pension-fund liabilities) is estimated at $2.2 trillion, roughly the same size as the global hedge-fund industry. Most are in network industries such as telecoms, electricity and transport. In addition, many countries have large minority stakes in listed firms. Those in which they hold a stake of between 10% and 50% have a combined market value of $890 billion and employ 2.9m people. The data are far from perfect. The quality of reporting varies widely, as do definitions of what counts as a state-owned company: most include only centralgovernment holdings. If all assets held at sub-national level, such as local water companies, were included, the total value could be more than $4 trillion. Reckons Hans Christiansen, an OECD economist. Moreover, his team has had to extrapolate because some QECD members, including America and Japan, provide patchy data. America is apparently so queasy about discussions of public ownership of -commercial assets that the Treasury takes no part in the OECD’s working group on the issue, even though it has vast holdings, from Amtrak and the 520,000-employee Postal Service to power generators and airports. The club’s efforts to calculate the value that SOEs add to, or subtract from, economies were abandoned after several countries, including America, refused to co-operate. Privatisation has begun picking up again recently in the OECD for a variety of reasons. Britain’s Conservative-led coalition is fbcused on (some would say obsessed with) reducing the public debt-to-GDP ratio. Having recently sold the Royal Mail through a public offering, it is hoping to offload other assets, including its stake in URENCO, a uranium enricher, and its student-loan portfolio. From January 8th, under a new Treasury scheme, members of the public and businesses will be allowed to buy government land and buildings on the open market. A website will shortly be set up to help potential buyers see which bits of the government’s /..337 billion-worth of holdings ($527 billion at today’s rate, accounting for 40% of developable sites round Britain) might be surplus. The government, said the chief treasury secretary, Danny Alexander, “should not act as some kind of compulsive hoarder”. Japan has different reasons to revive sell-offs, such as to finance reconstruction after its devastating earthquake and tsunami in 2011. Eyes are once again turning to Japan Post, a giant postal-to-financial-services conglomerate whose oftpostponed partial sale could at last happen in 2015 and raise (Yen) 4 trillion ($40 billion) or more. Australia wants to sell financial, postal and aviation assets to offset the fall in revenues caused by the commodities slowdown. In almost all the countries of Europe, privatisation is likely “to surprise on the upside” as long as markets continue to mend, reckons Mr Megginson. Mr Christiansen expects to see three main areas of activity in coming years. First will be the resumption of partial sell-offs in industries such as telecoms, transport and utilities. Many residual stakes in partly privatised firms could be sold down further. France, for instance, still has hefty stakes in GDF SUEZ, Renault, Thales and Orange. The government of Francois Hollande may be ideologically opposed to privatisation, but it is hoping to reduce industrial stakes to raise funds for livelier sectors, such as broadband and health. The second area of growth should be in eastern Europe, where hundreds of large firms, including manufacturers, remain in state hands. Poland will sell down its stakes in listed firms to make up for an expected reduction in EU structural funds. And the third area is the reprivatisation of financial institutions rescued during the crisis. This process is under way: the largest privatisation in 2012 was the $18 billion offering of America’s residual stake in AIG, an insurance company.Which of the following statements is not true in the context of the given passage ?
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