How campus recruitment norms are changing

Spending a major part of the last three years immersed in books was not, after all, a bad idea, feels J. Anusha, as she proudly flaunts the confirmation of her employment by an IT major recently. “I wanted to maintain an overall CGPA of 8.5. The grading which was introduced as many universities abroad insist on it has also come in handy for the recruiting firms,” says the final-year student of Sri Venkateswara College of Engineering.

With many software companies doing away with written tests for high scorers, there is a renewed emphasis on academic credentials, say college students and teachers. Scores in college have increasingly become a major filter during the recruitment of hundreds of students in two days, and sometimes, even in a day.
This year, TCS exempted students of top engineering colleges who have scored over 80 per cent in their course from the written test, while Cognizant has been doing the same with toppers in colleges for a few years now, say sources. “In reputable engineering colleges, there are often at least 50 students in a class of 120 that score over 80 per cent. But the interviews for students who were exempted were quite gruelling. Companies want to reduce their procedures, but won't compromise especially on the communication skills,” says R. Rajakumar, who got recruited in TCS.
“We know the companies are in a hurry so we give them a shortlist of eligible students who then undergo the recruitment procedure. It takes intelligent planning and partnerships by both placement officers of colleges and company personnel,” says Sathish Kumar, placement officer, St. Joseph's College, which placed around 591 students in Cognizant, and about 121 in Wipro this week.
Companies now have panels that have a mix of technical and HR personnel, so the student is tested on all areas in a short time. “Most companies that are allowed to come first often have a large recruitment plan,” says R. Samuel, a senior HR consultant with IT firms.
However, sources say that companies try not to rope in the top-rung performers (those who score 90 per cent and above), especially if they are among the first to recruit. “They know that these students would opt for core companies that come later,” says Amritha Srinivasalau, an engineering student. This is in the context of many colleges following the policy of dual placement that allows a student to appear for the recruitment tests of core companies, even if he/she is selected by an IT firm. Core companies are slated to start their procedures in most colleges only in December.
The eligibility criteria of companies are revised every year after studying the trends, says Mr.Samuel. Group discussions, once a part of the recruitment procedure of many companies, have been done away with by firms, though some, including Accenture and Capgemini, still lay stress on them.
Similarly, companies initially were reluctant to relax their requirement of a minimum of 60 per cent in every degree.
Now they do and some companies, including Wipro, allow one standing arrear and some even allow two. A minimum of just 50 per cent in class X and XII is acceptable too. “And a few including Cognizant offer a relaxation of five per cent in one degree, excluding the one that the student is pursuing, if he/she has secured over 60 per cent in all other areas,” says Mr.Samuel.
These relaxations, however, do not apply to graduates who apply to companies in off-campus procedures. “Even if the bulk recruitment paints a good picture of the industry, it involves only around 1.5 lakh engineers, just 20 per cent of the number of engineers who graduate every year. The others might have to undergo all of the tough procedures,” says Santanu Paul, CEO and Managing Director, TalentSprint, which trains unemployed graduates to make them employable in the IT industry. 

Proton-based chips could let machines talk with living things

Human devices, from light bulbs to iPods, send information using electrons. Human bodies and all other living things, on the other hand, send signals and perform work using ions or protons.

Materials scientists at the University of Washington have built a novel transistor that uses protons, creating a key piece for devices that can communicate directly with living things. The study is published in the journal Nature Communications.

Devices that connect with the human body's processes are being explored for biological sensing or for prosthetics, but they typically communicate using electrons, which are negatively charged particles , rather than protons, which are positively charged hydrogen atoms, or ions, which are atoms with positive or negative charge.

"So there's always this issue, a challenge, at the interface - how does an electronic signal translate into an ionic signal, or vice versa?" said lead author Marco Rolandi. "We found a biomaterial that is very good at conducting protons, and allows the potential to interface with living systems."

In the body, protons activate "on" and "off" switches and are key players in biological energy transfer. Ions open and close channels in the cell membrane to pump things in and out of the cell. Animals including humans use ions to flex their muscles and transmit brain signals. A machine that was compatible with a living system in this way could, in the short term, monitor such processes. Someday it could generate proton currents to control certain functions directly

QUESTION BANK FOR 6TH SEMESTER EEE(2008-12) WITH SYLLABUS

Hi guys sixth semester question bank as well as syllabus. It may be old for you 2010

SYLLABUS
ENGINEERING MANAGEMENT
MEASUREMENT AND INSTRUMENTATION
POWER SYSTEM ANALYSIS
ELECTRICAL MACHINE DESIGN
DIGITAL SIGNAL PROCESSING (QB- AVIT, VMKV) , (SOLUTION)

HOW LIGHTENING OCCURS / PRODUCTION OF LIGHTENING

All thunderstorms by definition produce lightning. Thunderstorms in the Southeast U.S. are common during the warm season. Therefore, everyone living in this area has experienced lightning at some point. It is an incredible natural phenomenon that amazes most. But, lightning is also very dangerous to humans, especially those involved in outdoor activities. Most people disregard the dangers of lightning because of the relatively low chance of being struck. However, lightning kills more people each year in the United States than all other weather events except flooding. On average, lightning kills 73 people annually. Injuries usually number in the hundreds. One question that is often asked is "Why do some storms produce a little lightning while others produce a tremendous amount?" Also, some have wondered whether there is a correlation between the amount of lightning and severe weather. The answer to these questions and others, including how to protect oneself from lightning, can better be answered with some background on how lightning works.

Introduction to Lightning Production 

The basic principle behind lightning is charge separation. This means a "pool" of positively charged particles becomes separated from a pool of negatively charged particles. A charge potential naturally develops when such a separation occurs. Basic electricity explains that if a charge potential between two areas in space becomes high enough, a discharge will occur. Since air is an insulator, the potential required for electricity to move through it is very high. If a discharge does occur between the two pools, it is called lightning. The obvious question is how does this charge separation get there in the first place?

The past fifty years of thunderstorm research have nearly unanimously concluded that the cloud charging process depends on ice collisions. So for lightning, ice must be present in a developing cumulonimbus and a large portion of the cloud needs to be well below freezing. Most cloud ice formation occurs between the temperatures of -10° and -40° C. Since the air normally cools with an increase in height, these temperatures are located many thousands of feet above the ground. A towering cumulus cloud needs to grow quite tall to reach this region of subfreezing temperatures. The cloud electrification process is not well understood, but is most likely caused by the collision of tiny ice particles and larger ice crystals. Tiny ice particles take on a positive charge during the collision, while the larger crystals are left with a negative charge. Since the smallest crystals are lighter, they are lofted into the upper portion of the cloud by the updraft. Hence, a pool of positive charge forms in the anvil region of the cloud, while the midlevels develop a negative charge pool. Of course, to get a significant separation of charge in the cloud, this collision process is occurring millions upon millions of times.

Diagram courtesy of COMET

So, once enough collisions have occurred, a large electrical potential has formed between the mid and upper levels of the cloud. Since the lowest portion of the cloud is charged negatively, positive charge in the Earth is attracted to its counterpart. Positive charge in the ground pools under the cloud, following the movement of the cloud. After enough cloud charging takes place, a discharge occurs between the cloud and the ground, to neutralize some of the charge.

Since these lightning bolts originate from a negatively charged portion of the cloud, they are termed "negative cloud-to-ground strikes." The vast majority of lightning from a mature thunderstorm originates from this portion of the cloud. They usually coincide with the rain and possibly hail falling from a storm. But, remember the positively charged ice particles that get lofted into the anvil? This charge can get isolated from the main updraft, so it is located well above the ground where a storm is sometimes not even apparent. Lightning also originates from the anvil, in the form of "positive strikes." These are almost always deadly due to the much higher amount of current required to reach the ground. Positive strikes are responsible for a large number of the annual death toll.

Variance in Lightning Strike Frequency 

The amount of lightning produced by any given thunderstorm can vary significantly. Since several important aspects of storm electrification are not well understood, the explanation for the variance in lightning frequency is also sketchy. A few hypotheses can be stated however. Most of the time, the amount of cloud-to-ground lightning produced by a storm is very similar to other storms on the same day in a similar air mass. Much research indicates that the efficiency of the ice forming processes in a thunderstorm correlate well with the amount of lightning produced. A high icing efficiency is usually achieved when the majority of the cloud is below -10° C. This type of environment often occurs during the spring and fall when the freezing level is closer to the ground. During the summer, icing efficiency can be achieved by a cool and dry layer aloft that enhances the ability of water to freeze.

Terrain such as mountains can also increase the amount of lightning yielded by a storm. Since storms initiate higher in the atmosphere above a mountain than over a plain, their updraft cores begin closer to the subfreezing layer. Forecasters at our office frequently notice cloud-to-ground strikes from very weak radar echoes over the mountains, while similar echoes over the low country are not producing any.

Large clusters of thunderstorms that commonly originate in the Plains states are notorious lightning producers. The flash frequency indicated by graphics from the National Lightning Detection Network is often tremendous, sometimes indicating greater than 5000 strikes in fifteen minutes! Those are usually spread over tens of counties, but nevertheless illustrate an amazing amount of electrical activity. Storm clusters are a large group of individual cells and updrafts, so there is an additive quality about their lightning production ability. Also, clusters are often tilted backward with height, so positive charge that gets lofted into the anvil can travel a significant distance behind the leading edge of the storms. This added charge separation seems to increase the total lightning strikes, especially the quantity of positive strikes from the anvils.

Lightning Safety

Protecting yourself and those whose safety you are responsible for is not too terribly difficult. It usually comes down to whether or not it is convenient. Usually, calling off a sporting event or changing your afternoon plans cannot depend entirely upon the forecast. Storms are very common in the Southeast on summer days. But, thunderstorms naturally provide a convenient warning about their approach: thunder! Generally, if you can hear thunder, you are at risk of being struck by lightning. A commonly misperceived notion is that it must be raining before you can get struck. A recent study found that most human lightning casualties occurred before and after the main rain core. Also, as mentioned earlier, positive strikes from the top of a thunderstorm usually strike areas quite distant from the parent storm. At least 10 percent of lightning strikes occur with no visible clouds overhead. Also, positive strikes are nearly always fatal to humans. So to avoid the risk of being struck by lightning, move to a substantial shelter or an enclosed vehicle until the storm passes and thunder can no longer be heard. If caught outdoors without adequate shelter, try not to be the tallest object. Crouch down in a grove of small trees, or at least get as low as possible and away from tall, isolated objects. Always avoid bodies of water such as pools, lakes and the ocean.

When indoors, a few safety rules should be followed as well. Since lightning is a potent source of electricity, it can move about poor electrical conductors with ease. If lightning strikes an object outside your house, it can travel inside via electrical wiring, plumbing, even clotheslines. Generally, avoid all contact or proximity to these types of conduits to vastly cut down on the risk. By remembering a few rules, the risk of being struck or affected by lightning can be greatly reduced. To minimize risk of damage to valuable indoor appliances, unplug as many as possible before a storm hits. Modern surge protectors cannot adequately protect electronics from lightning.

Lightning and Severe Thunderstorms

Lightning not only causes many deaths and injuries each year, but also much damage to property, especially electrical appliances. Numerous people, especially those who have lost property due to lightning, have suggested that the National Weather Service issue warnings for anomalous lightning activity. But, no research has yet linked thunderstorms' severity (hail, wind, tornadoes) to their quantitative lightning production. Although some severe thunderstorms produce an incredible amount of lightning, this is often because they have vigorous updrafts too. Since all thunderstorms produce lightning, which in turn can cause death and destruction regardless of quantity, we cannot issue warnings for lightning. On this note, reports to the NWS about lightning activity are of no use and actually disrupt our ability to warn for severe storms. Lightning activity is easily monitored remotely via the National Lightning Detection Network, displayed in a map format. Reports of hail, strong wind, flooding and storm rotation are much more useful because we cannot detect these events directly.

Conclusions

Lightning is a powerful yet incredible natural occurrence that affects almost everyone at some point in his or her life. From a safe indoor location, its beauty and grandeur can be marveled. Unfortunately, lightning deaths and injuries in the Southeast far outnumber other parts of the country. The main explanation for this is the high population density and large number of thunderstorm days. The abundance of outdoor activities in the Southeast, such as at lakes, sporting events, and farms also contribute to the higher casualties for the area. So, a greater public awareness is necessary to cut down on the number of lightning tragedies. It is imperative that coaches and leaders of outdoor activities be informed about proper lightning safety procedures. Individuals involved in such group activities will rarely if ever take the sole initiative to protect their own life by leaving prematurely. One primary mission of the National Weather Service is to inform the public of proper weather safety procedures to reduce or eliminate casualties. We hope that you will implement this information into your daily activities. 

Novel Magnetic, Superconducting Material Opens New Possibilities in Electronics

Scientists have reached a crucial milestone that could lead to a new class of materials with useful electronic properties. In research reported in the Sept. 5 issue of Nature Physics, the team sandwiched two nonmagnetic insulators together and discovered a startling result: The layer where the two materials meet has both magnetic and superconducting regions -- two properties that normally can't co-exist.Technologists have long hoped to find a way to engineer magnetism in this class of materials, called complex oxides, as a first step in developing a potential new form of computing memory for storage and processing.

The discovery, made by researchers at the Stanford Institute for Materials and Energy Science (SIMES), a joint institute of the Department of Energy's SLAC National Accelerator Laboratory and Stanford University, opens "exciting possibilities for engineering new materials and studying the interplay of these normally incompatible states," said Kathryn A. "Kam" Moler, the SLAC/Stanford researcher who led the imaging studies.

A critical next step: Figuring out whether the superconductivity and magnetism co-exist within the material in an uneasy truce, or whether this marks the discovery of an exotic new form of superconductivity that actively interacts with magnetism, said Moler. Superconducting materials, which conduct electricity with no resistance and 100 percent efficiency, normally expel any magnetic field that comes near them.

"Our future measurements will indicate whether they're fighting one another or helping one another," Moler said.

Independently, researchers from the Massachusetts Institute of Technology announced in the same issue of Nature Physics that they had confirmed the existence of magnetism at the interface between the two materials using an alternative means of measurement.

In a commentary accompanying both papers, Columbia University physicist Andrew J. Millis, who was not involved in the research, wrote that the work could introduce a new class of materials with "interesting, controllable, novel and perhaps useful collective electronic properties." While this goal is far off, he said, the new findings indicate that "the field has passed a crucial milestone."

SIMES graduate student Julie Bert, the paper's first author, and her colleagues made their observations on a thin film of lanthanum aluminate that had been laid onto a strontium titanate substrate. The structures were grown by researchers working with applied physicist Harold Hwang, who recently moved with his group from the University of Tokyo to join SIMES and now serves as deputy director. The atomic layer where the two oxides meet becomes metallic and allows current to flow with no resistance at temperatures close to absolute zero.

Researchers are starting experiments to see whether anything changes when the material is compressed, or when an electrical field is applied, said Moler. Additional research now must be done, she added, to determine the physical properties that contribute to forming both the magnetism and superconductivity in these oxides.

Innovation Is Step Toward Digital Graphene Transistors

Researchers are making progress in creating digital transistors using a material called graphene, potentially sidestepping an obstacle thought to dramatically limit the material's use in computers and consumer electronics.Graphene is a one-atom-thick layer of carbon that conducts electricity with little resistance or heat generation. After its discovery in 2004 -- which earned a Nobel Prize in physics -- it was touted as a potential replacement for silicon, possibly leading to ultrafast devices with simplified circuits that might be less expensive to manufacture.

However, graphene's luster has dulled in recent years for digital applications as researchers have discovered that it has no "band gap," a trait that is needed to switch on and off, which is critical for digital transistors.

"The fact that graphene is a zero-band-gap material by nature has raised many questions in terms of its usefulness for digital applications," said Purdue doctoral student Hong-Yan Chen.

Electrons in semiconductors like silicon exist at two energy levels, known as the valence and conduction bands. The energy gap between these two levels is called the band gap. Having the proper band gap enables transistors to turn on and off, which allows digital circuits to store information in binary code consisting of sequences of ones and zeroes.

Chen has led a team of researchers in creating a new type of graphene inverter, a critical building block of digital transistors. Other researchers have created graphene inverters, but they had to be operated at 77 degrees Kelvin, which is minus 196 Celsius (minus 320 Fahrenheit).

"If graphene could be used in digital applications, that would be really important," said Chen, who is working with Joerg Appenzeller, a professor of electrical and computer engineering and scientific director of nanoelectronics at Purdue's Birck Nanotechnology Center.

The Purdue researchers are the first to create graphene inverters that work at room temperature and have a gain larger than one, a basic requirement for digital electronics that enables transistors to amplify signals and control its switching from 0 to 1.

Findings were detailed in a paper, "Complementary-Type Graphene Inverters Operating at Room-Temperature," presented in June during the 2011 Device Research Conference in Santa Barbara, Calif.

Thus far graphene transistors have been practical only for specialized applications, such as amplifiers for cell phones and military systems. However, the new inverters represent a step toward learning how to use the material to create graphene transistors for broader digital applications that include computers and consumer electronics.

To create electronic devices, silicon is impregnated with impurities to change its semiconducting properties. Such "doping" is not easily applicable to graphene. However, the researchers have potentially solved this problem by developing "electrostatic doping," which makes it possible for graphene inverters to mimic the characteristics of silicon inverters.

Electrostatic doping is induced through the electric field between metal gates, which are located 40 nanometers away from graphene channels. The doping can be altered by varying the voltage, enabling researchers to test specific doping levels.

"This will allow us to find the sweet spot for operating the device," Chen said.

How to crack Civil Service exams?

Comprehensive study of topics plus being up-to-date with events of the day is crucial to cracking the Civil Services Main exam, say experts.

The Civil Services (Main) Examination 2011 is just a few weeks away. Over the years, there has been a rise in preparation awareness among civil service aspirants, but this coveted exam continues to throw a surprise element calling for newer strategies.

The question papers in recent years have clearly shown that the Union Public Service Commission (UPSC) seems to be determined to select those aspirants who are able to cover most of the topics in the syllabus with focus on current affairs.

The number of questions in the General Studies question papers has been doubled from 30 to 60, says P.S. Ravindran, director, Vajiram and Ravi Institute for IAS Examination, New Delhi. “As UPSC covers a large number of areas, General Studies preparation should be comprehensive,” he says.

He stressed the need to score more than 320 marks in both the optional subjects as scoring in the General Studies has become more challenging.

A sizeable number of candidates in the previous mains examination were not able to score more than 270 out of 600 in the General Studies papers.

Many questions pertaining to current affairs of the month of October 2010 were unexpected and candidates found it tough to handle them in the previous mains.

Aspirants who were able to read at least two broadsheet newspapers such as The Hindu regularly were able to answer those questions. “Reading of two newspapers and Frontline is necessary. Questions based on less prominent news is also being asked,” says Mr. Ravindran.

Instead of reading several study materials, candidates are advised to select two source materials and concentrate on that with four rounds of quick revision.

A thorough preparation of topics covered in statistics and Indian Economy is crucial for a high score. The questions would cover Indian economy and issues relating to planning, mobilisation of resources, growth, development and employment.

Issues arising from the social and economic exclusion of large sections from the benefits of development, economic and trade issues such as foreign trade, foreign investment, economic and diplomacy issues relating to oil, gas and energy flows, the role and functions of IMF, World Bank and WTO which influence India's economic interaction with other countries and international institutions are important.

The candidates who score more than 300 in the General Studies papers are those with excellent understanding of the subjects at the secondary and higher secondary school level.

They do not require any specialised study in any of the subjects for the General Studies. NCERT books of history, geography, polity, economy and statistics continue to be useful for revising the syllabus for the main examination.

Current affairs based on newspaper reports from September 2010 to October 2011 are the key areas. The candidates should be able to think and formulate views based on their subject knowledge based primarily on NCERT material.

Last year, questions on news covered in the period between October 1 and 15 took candidates by surprise.

More surprises may be in store for them this year. UPSC is expected to continue testing the analytical mindset of candidates in this main exam too. Environment, ecology, biodiversity and climate change may be prominent areas.

Reading editorials of newspapers has been found helpful for Essay paper and for answering questions on polity and social issues.

Economic Survey and publications such as Yojana may be useful. Lok Sabha channel debates may throw light on social issues. Weekly group discussions or joint study with other candidates would enrich the understanding of key areas.