Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C ? ?->(Show Answer!)

1. Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C ?

Write Comment

Comments

Tags

Show Similar Question And Answers

QA->Whose pen name is known as ‘Just as I would not like to be a slave, so I would not like to be a master’ ?....

QA->Sodium/Potassium salt of stearic acid, palmitic acid and oleic acid is-....

QA->Cylinder block construction by mono-block is preferred to individual cylinder construction because of?....

QA->Which material is suitable for water purification?....

QA->Which Indian airport was presented the award for the world’s best airport, under the category of handling 25 to 40 million passengers per annum?....

MCQ->Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C ?....

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:
....

MCQ-> on the basis of the information given in the following case. Teknik Group of industries had businesses in different sectors ranging from manufacturing, construction, fish farming and hotels. These different businesses operated as semi-independent units managed by the unit level managers. Teknik’s management had an internal consultancy group called as Business Advisory Group (known internally as BAG). The 15 experts in BAG were hired personally by Mr. Teknikwala, the owner of Teknik, who wanted this core group of experts to help his organization grow fast without facing the typical growth hurdles. Most of them were specialists in fields like law, information technology, human resource management, and operations management. Almost all of them had experience spanning decades in the industry. Whenever any of the units faced any significant all units and it represented an extra work for those who were involved. This coordination was required to understand the different work processes and the users’ requirements. This coordination activity was being extensively managed by the old timers as they were familiar with internal processes and people in the different units. An external consultant was also hired for customization and implementation After two months, BAG teams had to fortnightly present their progress to Ms. Teknikwali’s team. In the last meeting Ms. Teknikwali was dissatisfied. She explained her thinking that since ERP impacted every aspect of the business, the roll out had to be done faster. She wanted Mr. Shiv to get the implementation completed ahead of schedule. In the meeting she asked Mr. Shiv to get the people in IT team to be more productive. Not willing to disagree, Mr. Shiv committed to a roll-out schedule of complete ERP system in 6 months instead of earlier decided 14 months. Next day, Mr. Shiv presented the revised project milestone to BAG members. He told them that in order to meet the deadline, the members were expected to work on week-ends till the completion of the project. Along with that, they were also expected to maintain their earlier standards of delivery time and quality for the normal trouble-shooting and internal advisory work. Mr. Shiv also pointed out that anyone whose performance did not meet the expectations would be subjected to formal disciplinary action. The meeting ended without any member commenting on Shiv’s ideas, although Mr. Shiv heard a lot of mumbling in the corridor. Over the week, Shiv noticed that the members seemed to avoid him and he had to make extra effort to get ideas from them. After a fortnight Shiv reviewed the attendance register and found the Mr. Lal, an old time member, had not come during the week-ends and certain decisions were held up due to lack of inputs from Mr. Lal. Mr. Shiv issued a written reprimand to Mr. Lal. He was speechless on receiving the reprimand but kept silent. It has been three days since that incident. Some of the senior members had put in request for transfer to other business units. It was rumoured that four problems, the unit level managers would put up a request for help to BAG. The problems ranged from installation of internal MIS systems, to financial advice related to leasing of equipment, to handling of employee grievances. Over a period of 20 years, Teknik’s revenues grew from 100 crore 10,000 crore with guidance of BAG and due to Mr. Tekinwala’s vision. Given its reputation in the industry, many people wanted to start their careers in BAG. Often young MBAs fresh out of business schools would apply. However their applications used to be rejected by Mr. Teknikwala, who had a preference for people with extensive industry experience. Things changed after the unfortunate demise of Mr. Teknikwala. His daughter Miss. Teknikwali took up the family business. She was an MBA from one of the premier business schools, and was working in a different company when Mr. Tekinwala passed away. She preferred that BAG developed new ideas and therefore inducted freshly graduated MBAs from premier business schools. She personally supervised the recruitment and selection process. Now the entire group constituted of 50 specialists, out of which 35 were the old time members. She also changed the reporting relationships in the BAG group with some of the older members being made to report to the new members. In IT team, Mr. Shiv, a newly recruited MBA, was made in-charge. For the older members it was a shock. However, as most of them were on the verge of retirement, and it would be challenging to search for new jobs while competing with younger professionals, they decided to play along. After one month, all business units were caught up in the ERP fever. This was an idea pushed by Ms. Teknikwali who the need the need to replace the old legacy systems with latest ERP system integrating all the units of Teknik. This was heavily influenced by her experience in the previous where an ERP system was already up and running. Therefore she was not aware of the difference between installing an ERP system and working on an already installed one. The ERP mplementation in Teknik Group required extensive coordination with senior level managers of senior legal experts had agreed to an offer from a law firm. Other senior members would sporadically come in late to work, citing health reasons. Almost all senior members now wanted a weekly work-routine to be prepared and given to them in advance so that they could deliver as per the schedule. This insistence on written communication was a problem as urgent problems or ad-hoc requests could not be foreseen and included. Also normal services to other business units were being unattended to, and there were complaints coming from the unit heads.Which of the following could have been a better response of Mr. Shiv to Ms. Teknikwali’s request to re-schedule the ERP implementation?....

MCQ-> Read the following passage to answer the given questions based on it. Some words/ phrases are printed in ‘’bold’’ to help you locate them while answering some of the questions.The e-waste (Management of Handling) Rules, 2011 notified by the Ministry of Environment and Forests, have the potential to turn a growing problem into a developmental opportunity. With almost half-a-year to go before the rules take effect, there is enough time to create necessary infrastructure for collection, dismantling, and recycling of electronic waste. The focus must be on sincere and efficient implementation.Only decisive action can reduce the pollution and health costs associated with India’s hazardous waste recycling industry. If India can achieve a transformation, it will be creating a whole new employment sector that provides good wages and working conditions for tens of thousands. The legacy response of the States to even the basic law on urban waste , the Municipal Solid Wastes (Management and Handling) Rules, has been one of the indifference many cities continue to simply burn the garbage or dump it in lakes. With the emphasis now on segregation of waste at source and recovery of materials, it should be feasible to implement ‘’both sets of rules’’ efficiently. A welcome feature of the new e-waste rule is emphasis on extended producer responsibility. In, other words, producers must take responsibility for the disposal of end-of-life products. For this provision to work, they must ensure that consumers who sell scrap get some form of financial incentive. The e-waste rules, which derive from those pertaining to hazardous waste, are scheduled to come into force on May 1, 2012. Sounds as they are, the task of scientifically disposing a few hundred, thousand tonnes of trash electronics annually depends heavily on a system of oversight by State Pollution Control Boards (PCBs). Unfortunately, most PCBs remain unaccountable and often lack the resources for active enforcement. It must be pointed out that, although agencies handling e-waste must obtain environmental ‘’clearances’’ and be authorised and registered by the PCBs even under the Hazardous Wastes (Management, Handling and Transboundary Movements) Rules, 2008, there has been little practical impact. Over 95 per cent of electronic waste is collected and recycled by the informal sector. The way forward is for the PCBs to be made accountable for enforcement of the e-waste rules, and the levy of penalties under environmental laws. Clearly, the first order priority is to create a system that will absorb the 80000-strong workforce in the informal sector into the proposed scheme for scientific recycling. Facilities must be created to upgrade the skills of these workers through training and their occupational health must be ensured. Recycling of e-waste is one of the biggest challenges today. In such a time, when globalization and information technology are growing at a pace which could only be imagined few years back, e-waste and its hazards have become more prominent over a period of time and should be given immediate attention.What according to the passage is important now for e-waste management?
....

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.As increasing dependence on information systems develops, the need for such system to be reliable and secure also becomes more essential. As growing numbers of ordinary citizens use computer networks for banking, shopping, etc., network security in potentially a ‘’massive’’ problem. Over the last few years, the need for computer and information security system has become increasingly evident, as web sites are being defaced with greater frequency, more and more denial-of-service attacks are being reported, credit card information is being stolen, there is increased sophistication of hacking tools that are openly available to the public on the Internet, and there is increasing damage being caused by viruses and worms to critical information system resources.At the organizational level, institutional mechanism have to be designed in order to review policies, practices, measures and procedures to review e-security regularly and assess whether these are appropriate to their environment. It would be helpful if organizations share information about threats and vulnerabilities, and implement procedures of rapid and effective cooperation to prevent, detect and respond to security incidents. As new threats and vulnerabilities are continuously discovered there is a strong need for co-operation among organizations and, if necessary, we could also consider cross-border information sharing. We need to understand threats and dangers that could be ‘’vulnerable’’ to and the steps that need to be taken to ‘’mitigate’’ these vulnerabilities. We need to understand access control systems and methodology, telecommunications and network security, and security management practise. We should be well versed in the area of application and systems development security, cryptography, operations security and physical security.The banking sector is ‘’poised’’ for more challenges in the near future. Customers of banks can now look forward to a large array of new offerings by banks, from an ‘’era’’ of mere competition, banks are now cooperating among themselves so that the synergistic benefits are shared among all the players. This would result in the information of shared payment networks (a few shared ATM networks have already been commissioned by banks), offering payment services beyond the existing time zones. The Reserve Bank is also facilitating new projects such as the Multi Application Smart Card Project which, when implemented, would facilitate transfer of funds using electronic means and in a safe and secure manner across the length and breadth of the country, with reduced dependence on paper currency. The opportunities of e-banking or e-power is general need to be harnessed so that banking is available to all customers in such a manner that they would feel most convenient, and if required, without having to visit a branch of a bank. All these will have to be accompanied with a high level of comfort, which again boils down to the issue of e-security.One of the biggest advantages accruing to banks in the future would be the benefits that arise from the introduction of Real Time Gross Settlement (RTGS). Funds management by treasuries of banks would be helped greatly by RTGS. With almost 70 banks having joined the RTGS system, more large value funds transfer are taking place through this system. The implementation of Core Banking solutions by the banks is closely related to RTGS too. Core Banking will make anywhere banking a reality for customers of each bank. while RTGS bridges the need for inter-bank funds movement. Thus, the days of depositing a cheque for collection and a long wait for its realization would soon be a thing of the past for those customers who would opt for electronic movement of funds, using the RTGS system, where the settlement would be on an almost ‘’instantaneous’’ basis. Core Banking is already in vogue in many private sector and foreign banks; while its implementation is at different stages amongst the public sector banks.IT would also facilitate better and more scientific decision-making within banks. Information system now provide decision-makers in banks with a great deal of information which, along with historical data and trend analysis, help in the building up of efficient Management Information Systems. This, in turn, would help in better Asset Liability Management (ALM) which, today’s world of hairline margins is a key requirement for the success of banks in their operational activities. Another benefit which e-banking could provide for relates to Customer Relationship Management (CRM). CRM helps in stratification of customers and evaluating customer needs on a holistic basis which could be paving the way for competitive edge for banks and complete customer care for customer of banks.The content of the passage ‘’mainly’’ emphasizes----
....