sync iv

SYNC 2012, MESA 1

`Message froM the hoD, Mech. engg.

I am happy to see that the fourth volume of SYNC has been brought out by Mechanical Engineering Students’ Association (MESA). I take this opportunity to congratulate all the team members and the

publication team in particular for their commendable effort in bringing out the fourth successful issue of SYNC. For the last three years, SYNC as an e-magazine has been serving as a useful platform for exchanging ideas and information among the IITG community and with outer world also. Last three editions of SYNC have been quite successful. In this volume of SYNC, there are articles ranging from popular topic to latest development in mechanical engineering in one end and from cross words to poems on the other. I am sure with this gamut of content this volume of SYNC will be acceptable to even more and more readers.

I hope you all will enjoy reading this issue of SYNC like the earlier issues and will also contribute to successful future editions.

Debabrata Chakraborty

Professor & Head

Department of Mechanical Engineering

I am glad to see the Mechanical Engineering Students’ Association (MESA) of IIT Guwahati bringing out the fourth edition of its e-magazine, SYNC. The published articles encompass a range of

topics to suit to the taste of a general technoscientific community. Apart from shedding some light on few interesting developments related to science and technology, it also covers few general topics, extracurricular activities, informative articles as well as valuable experiences of our faculty members. In short, the magazine continues to act as a platform for sharing knowledge, experience and activities.

I would like to extend my hearty congratulations to the publication committee, the authors and the entire team of MESA for their commendable efforts in successfully bringing out the e-magazine. I would also like to express my sincere thanks to Prof. D. Chakraborty, Head of ME and the colleagues in the department for their constant support and valuable suggestions for publication of the magazine. Hope you enjoy reading that would encourage bringing out future editions!

Dr. Ashis K Sen

Faculty Advisor,

MESA

Message froM the faculty aDvisor

SYNC 2012, MESA 1 2 Indian Institute of Technology, Guwahati

`Message froM the Publication secretary

Voices and thoughts have the undeniable power to illuminate, stimulate and animate. But for that

to happen they need expression, they need words. And words need a medium to float, to reach and to conquer. For centuries, thoughts and voices have propagated through necessary media in the form of words to shape the world. Wielders of pen have often been the makers of men.

We, as a part of MESA, endeavor to provide a medium for propagation of knowledge and at the same time a platform for self-expression under the name SYNC. In its fourth edition, the magazine tries to explore entropy outside the books, explain the Formula 1 aerodynamics without the formulae, delve into the design highlights of the Boeing 787 Dreamliner, and offer lists of car doors and crashworthy car safety mechanisms. It caters to the technology enthusiasts with its articles on Fly-By-Wire flight control systems, animal robots, and the ironman technology. It has yummy inclusions of stories behind ‘serendipitously’ delicious snacks. It also includes diaries which tell the tales of internship experiences of our seniors. This volume of SYNC, as it has been a trend, tries to cut across diverse domains of science and simultaneously express subjective views.

I take this opportunity to thank the Head of the Department and Faculty Advisor for lending their constant support for the all the activities of the association. I am grateful to the members of the writing and editing team for gracing this magazine with their valuable contribution. I feel deeply thankful to the designers who fabricated the magazine to its current form.

Taking inspiration from Richard Wright’s famous words from American Hunger, I would like to hurl words into the darkness and wait for an echo and if an echo sounded, no matter how faintly I would send other words to tell, to march, to fight, and to create a sense of hunger in life that gnaws in us all. Like every year, we would continue to serve as a medium for voices and ideas to flow to reach the ones who listen, and for whom words continue to create and satisfy the hunger for knowledge.

Feeling immense pride (and waiting for the echoes), I present to you SYNC, Volume IV.

Nitin Khola,

Publication Secretary

MESA

TEAM SYNC’12

Head of the DepartmentProf. Debabrata

Chakraborty

Faculty Advisor, MESADr. Ashis Sen

Publication SecretaryNitin Khola

MembersAnupam SinghalAdnan AkhtarN.R.Sreeram

Vasu GoelVibhor Kalra

Hemant AgrawalNipun Sareen

Vamshi KrishnaPriti Choudhary

Siddharth NambiarVivek Chowdhary

Abhinav YadavNavdeep Sharma

Avinash YadavAngshuman

RamnathJyotishman Sarma

DesignersHemant Agrawal

Tushar Chhabra (Cover)

Association Members

President, MESARavish Vasan

Vice President, MESATushar Mane


MESA Activities

Fresher’s Orientation

Internship Talk


F1 Aerodynamics Simplified

Car Doors

The New Age Circuit

Fly By Wire

Enercon E-126

Crashworthiness

Boeing-787 Dreamliner

3D Technology

Iron Man Technology

Entropy in Real life

L’arte Della Meccanica

Animal Bots

Training the Brahmaputra

Poem: Reminiscence

Intern Diaries

Contents05

07

10

11

14

19

23

27

33

37

17

21, 29

25

31

35

SYNC 2012, MESA 5

`

F1 AERODYNAMICS Simplified

Formula One today, is arguably one of the most technologically advanced sports in the world. The term ‘Aerodynamics’ is an integral

part of this high profile sport. So much so, that many enthusiasts consider it a part of the F-1 jargon.

It wasn’t always like this though. Prior to 1967, most cars made very little use of Aerodynamics. The focus was mostly on generating the maximum possible straight line speed and minimizing the drag. However, like in every other field, Formula One had its own thinkers and revolutionaries. They began attempting to modify the dynamics of the car, such that it would improve the speeds of the car while taking a turn. And this was when the era of ‘Downforce’ in Formula One began.Downforce equates to an extra amount of force pushing down on the car. This naturally helps during cornering as the increased frictional force (and hence

centripetal acceleration) facilitates the faster turning of the car. However, bear in mind that an increase in downforce inadvertently results in an increase in drag, which by no means, is desirable. And this led to the formulation of one of the biggest challenges in Formula One till date - Optimization in the levels of Downforce and Drag. Over the years teams have done a lot of things to reduce drag and increase top speed while still trying to maintain that right amount of downforce. Some of the methods are what you probably expected to see while others are a little more off the wall. In no particular order here are some of my favorites!

The moveable Rear Wings (DRS)

It’s only fitting that the DRS flags off this topic of discussion. After all, with all the controversy that has surrounded it during the past one year, this is least that we can do for it. Observe the two images carefully. The most general function of the Rear wing on an F1 car is to generate downforce by smoothening the airflow over the car. When the rear wing is opened, the air flow is disrupted, thus reducing the downforce and eventually decreasing the drag. This ingenious mechanism has made its way into the FIA rulebook for the 2011 season.

-SIDDHARTH NAMBIAR


`

`Infamous Tyre SwapBack in the 1990’s, the Tyrrell Racing team decided to run the front wheels and tires at the rear end. This led to a decrease in front area of the car, which decreased the drag. However, tire supplier Goodyear told the FIA that the rubber was not suited to putting the power down and the concept was banned.

No rear wing?Some circuits like Hockenheim and Monza demand high speed and low amount of downforce. Hence the pundits thought, ‘Why not remove the Rear wings entirely?’ The fastest Formula 1 car of all time is the BAR-Honda 067 “Lakester” of 2005. It achieved 257mph on an airport runway in the USA. It did not feature a rear wing at all, as there was nothing in the Formula 1 rule book that said

it had to - Whoever said that a professional doesn’t ‘cheat’!

The SlipstreamMaking use of the slipstream has always been considered an important art in Formula One. In fact, many teams run specific tests to improve the advantage available to them on making use of the slipstream. The slipstream works on the concept of ‘drafting’, a term that is commonly encountered in a NASCAR race. In the region immediately behind a car, a ‘wake’ is produced. This is a low pressure region. A car that is closely following the car in front, always tries to enter this ‘wake’ region. The low pressure region produces a net suction effect and ‘pulls’ the trailing car closer to the leader. While it’s pretty simple theoretically, you would have to be very brave to get that close and pull off a perfect overtake.

The Double Diffusers

The picture here describes the Double Diffusers perfectly. The FIA rulebook specified that the diffusers must not cross a certain height from the ground. And most teams, (Like Ferrari, shown on the right) adhered to that.

However, some teams like Brawn and Toyota exploited the fact that nothing was specified about aerodynamic structures that could be used in the central region just below the crash structure (The grayish thing).

What can you say about Brawn GP? They raced for just one season, and were crowned world champions. This was the year of the Double Diffusers. However, the fact remains that despite not being the only team to use the double diffusers, Brawn was the only team to outrace the Ferraris and McLarens time and again.Toyota, Brawn and Williams exploited a loophole in the rules that says that the diffuser is merely one section of the wider bodywork structure and cleverly shaped the rear crash structure (the rectangular grayish structure just above the yellow) so that it effectively lengthens and heightens the diffuser’s central section. This increased the overall area of the Diffuser and increased Downforce by a significant amount. Truly, this was ruthless technological innovation at its best.

SYNC 2012, MESA 7

`

CAR DOORS

While zooming across the road at lightning speed in NFS (and at times seemingly violating gravity!) or while watching Rajnikant get

out of his car in slow motion, we rarely care about how complex a car is, we rarely wonder that there can possibly be an entire world of engineering behind a seemingly simple part of a car, namely the door! The designing of doors plays a very important role in car manufacture since it involves the safety of the passengers. Starting from the “suicide” doors of the Ford Thunderbird to the “scissor” doors of the Lamborghini, this field has seen extensive development and amelioration both in terms of style and mechanism.

SCISSOR DOORSScissor doors are automobile doors that rotate

vertically at a fixed hinge at the front of the door, instead of swinging outward as in the cars we presently see. This type of doors is extremely popular through the Lamborghini car series. The first vehicle to feature scissor doors was the Alfa Romeo Carabo concept car, by Marcello Gandini. Gandini's desire for an innovative design, and concern over the car's extremely poor rear visibility made him innovate the design. The driver could easily lean out of the car for facilitating rear view of the vehicle.

ProsOpen driving: The vehicle can be moved even with the doors open, without any hazard of hitting.Easy parking: It is useful while parking in tight spaces.Convertible Possible: The hinge is placed in a similar location to a conventional door, so a convertible version of the car is possible with the same door style.No knock-into: It reduces the ‘dooring’ hazard to cyclists.

ConsTime to get in, time to get out: The door restricts quick access.Extra notes: The design pushes up the costs.Ceiling limit.Emergency ‘non-exit’: In the event of a rollover, the exit becomes almost impossible.

-RAMNATH


`

`BUTTERFLY DOORSButterfly doors are generally seen on high-

performance automobiles. Similar to scissor doors they move upwards and in addition to it, open outwards. The McLaren F1, Enzo Ferrari, Toyota Sera and the Mercedes-Benz SLR McLaren, use butterfly doors. The Mercedes-Benz SLR McLaren Roadster was one of the few open top cars to use butterfly wing doors. The doors are hinged at the side of A-pillar instead of at top by the roof.

ProsThe Butterfly effect: The doors are stunning to look at are bound to catch attention when they open vertically.The duality: These doors come with added advantages of scissor doors and regular outward-opening doors.

ConsCostly Affair: These doors ask for fat price.s.

SUICIDE DOOR

A suicide door is a car door hinged on the edge closer to the rear of the vehicle. Such doors are rarely used on vehicles in modern times because of their disadvantages.

They were especially popular in the gangster era of the 1930s –because "It's a lot easier to shove somebody out with the wind holding the door open", as Dave Brownell, the former editor of Hemmings Motor News stated.

The last independently opening suicide doors on a mass produced car were fitted on the Ford Thunderbird, after which the 1971 model was the last American production automobile to feature rear suicide doors, because after this time, safety concerns prevented their use.

ProsEasy-in-Easy-out: Rear-hinged doors make entering and exiting the vehicle much easier.Easy chauffeuring: Rear-hinged back doors (in combination with front-hinged front doors) make exiting easier for the driver, who can then reach the handle of the back door to open it for the passenger.

ConsSimultaneity hindered: Attaching hinged doors in front and suicide doors in the back makes it difficult for passengers to exit from the front and rear seats simultaneously due to the limited space.Injury-prone exiting: If the user exits the vehicle while it is moving forward, the door will hit him or her upon exit.

SYNC 2012, MESA 9

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`CANOPY DOORS

A vehicle canopy is a rarely used type of door for cars. A canopy is a type of door which sits on top of a car and lifts up. They can be hinged at the front, side, or back. Canopy doors are rarely used on production cars. They find applications in non-commercial areas. Various models of the Batmobile used in the production of the Batman films make use of the canopy door.

ProsNo blocking: They do not obstruct the road or pavement when opened as they open vertically.Field of view: A-pillars aren't necessary as there are no side doors, so the windscreen can extend from the front to the back of the car, giving the driver a wide field of vision.

ConsLocal warming: Air-conditioning or climate control is necessary because the canopy provides substantial 'glasshouse effect'. Emergency ‘non-exit’: If the car rolled over during fast cornering, exiting the vehicle would be impossible.Pangs of weather: In situations of bad weather such as snow, rain, or hail, it is impossible to enter or exit the vehicle without getting the interior wet, unless under cover.

SLIDING DOOR

A sliding door is a type of door that opens by sliding (usually horizontally). The door is either mounted on or suspended from a track. They are

most commonly used for minibuses and buses to provide a large entrance or exit for passengers without obstructing the pavement. They are often used on the side of commercial vans as well, as this allows a large opening for equipment to be loaded and unloaded without obstructing access.

ProsNo obstruction: The doors provide no obstruction to fellow riders on road when opened.Easy access: The passengers feel ease in getting in and getting out of these doors.

ConsExtra Effort: Compared to traditional doors, it takes more physical strength to pull the sliding door open and back.The ‘Big’ Problem: Requirement of space to the rear and height to the side restricts the doors to large sized cars.


Formula One Racing - The escalating craze is finally flaming the streets and a billion hearts of India with surreal excitement. It is giving birth to never ending

craze and never ceasing enthusiasm. Doesn't that seem splendid indeed?

The New-Age Circuit:

RevolutionisinG INDIA

`For the first time in the history of Formula One Racing, India witnessed the éclat of a dream to host the “Indian Grand Prix 2011.” The Indian F1 Race occurred as the 17th round of the 2011 FIA Formula1 World Championship. Breaching all constraints, the race was held at 'Buddh International Circuit' in Greater Noida, 24 km from

Delhi. The word ‘Buddh’ is derived from Lord Buddha, the founder of B u d d h i s m which had its origin in

India. Since he taught about love and compassion, the logo gets a heart shape which conveys the feeling. The tricolour in the logo is a tribute to our National flag. The racing circuit is 5.137 kilometres (3.19 mi) and is designed by eminent F1 circuit designer Hermann Tilke. With 60 laps of gameplay, the race length for ‘The 2011 Indian Grand Prix’ accounts to 308.4km (191.6 mi). The sprawling track runs over an area of 875 acres in the outskirts of the city. The track furnishes an initial seating capacity of 1,50,000 and promises to accentuate the same to an immense figure of 2,00,000 in due course of time. This tantalizing circuit is a part of Jaypee Green Sports city and will also be used for hosting one or more rounds of Moto GP championships in the year 2012. The Indian construction company Jaiprakash Associates has signed the 10-year contract for the race. The track has 16 largely medium speed corners where F1 cars will lap at an average speed

of 210 km/h. The back straight will let F1 cars reach an amazing velocity of 320 km/h making it one of the fastest tracks in the world. The expected F1 car lap time is 1 minute 24 seconds. The organizers have also taken feedback from teams which have done the track analysis via simulators leading to modification of the turn 7 in order to maximize overtaking opportunities into banked turn 10 which will make the race more exciting. A grand stand with a capacity of 13,000 will overlook the turn 10 and turn 11 giving the F1 fans an opportunity to be a part of this grand action.

This heralds the beginning of a new-age transient racing experience. India has entered a new vista of excellence and has made an imprint in the field of International Formula One racing. Not only would this boost the hotel and tourism industry but also escalate India’s profile on the ladder of development. India hallmarks a niche of its own racing with all other developed countries of the world.Sources: http://www.jaypeesports.com/jaypee-race-circuit.shtml

-ANGSHUMAN


`

FLY BY WIRE

Fly-By-Wire (FBW) Primary Flight Controls have been used in military applications such as fighter airplanes for ages. Recently they have also been employed in

commercial transport application. The introduction of this technology has been a watershed development in aircraft evolution and has enabled advances to be made which were not possible before. But what exactly is ‘Fly-By-Wire’ technology?

In the early times of aviation, aircraft flight controls were purely mechanical systems comprising pulleys and cables deflecting the aircraft’s control surfaces about their hinges. The control stick inputs given by the pilot counteracted the aerodynamic forces acting on these control surfaces. Until 1960, the capabilities and handling qualities of flight control systems were enhanced by introducing hydraulic actuators and gyroscopic sensors. It was in the early 1980’s that the first aircraft incorporating Fly-By-Wire control systems became operational. In FBW control system, the cable control of primary control surfaces is removed. Rather, the actuators are controlled electrically. At the heart of the FBW system are electronic computers which gather information from on-board sensors and position transducers attached to the pilot’s controls and convert them into commands that are transmitted to the actuators. All the inputs are processed by control law algorithms resulting in electric outputs to the actuators. The onus of control

is shifted from the control surfaces to the flight control systems, opening new avenues for design. Restrictions on aircraft design for natural stability are drastically reduced

enabling the designers and giving them the freedom to design more efficient airplanes with higher thrust-to-weight ratios. The aircraft can also be designed to have a negative stability over a range of speed

and height conditions.

Flight Control : Evolution

“You know what the F-16 pilots say: ‘You don't fly an F-16; it flies you.’ Aircrafts like F-16 and Eurofighter Typhoon are designed for great agility, reduced drag and an overall increase in lift at the cost of aerodynamic stability. And to achieve all this with better control, they have complex Flight Control Systems such as ‘Fly by wire’.”

-PRITI CHOUDHARY


`Computers react quicker than a pilot!

The FBW control system provides automatic stabilization of the aircraft atoning for the loss of natural stability and thus enabling lighter aircrafts to be made with better overall performance. The reaction time of the control laws is much faster than that of an alert pilot. Therefore, the size of the flight control surfaces can be made smaller than that required for a conventionally controlled

airplane. This results in an overall reduction in the weight of the system. The FBW technology has led to complete elimination of complex mechanical controls and linkages. A Fly-By-Wire control system mainly comprises of:

Electric Data Transmission: A key element in a FBW system, it is mainly done in modern aircrafts using a serial digital data transmission system with time division multiplexing.

Control Surface Actuation: Controlling movements of the control surface is a vital element of FBW system. It is mainly done by a two stage servo system.

Motion Sensor Feedback: Any change in the motion of the aircraft resulting from a disturbance of any sort is immediately sensed by the motion sensors, the computer then moves the appropriate control surface to apply forces and moments to correct the deviation from commanded flight path.

Air Data: Control surface effectiveness of an aircraft varies with its flight envelope of height and speed combinations. This variation can be as high as 40:1 over the entire flight of the aircraft. It is thus necessary to adjust control surface deflection according to aircraft’s speed and height in order to achieve a stable closed loop control system.

The Ups

The advantages of a well-designed FBW control system are manifold. This technology is an essential component of high-performance jets which are built to be highly maneuverable, which also makes them more unstable in flight. They require fine, almost constant adjustments to stay on course, which is easy for fly-by-wire systems and would be almost impossible for human pilots with even the fastest reaction times. Fly-by-wire systems give pilots the freedom to focus on weapons and tactics and can save pilots from trouble by monitoring more systems and catching problems they might not notice.

The DownsThe ease and comfort provided by this technology has indeed come with a price. It has created a new class of safety concerns that requires new methods of analysis. The primary difficulty with this new and complex


`technology is that it is only as good as the programmers and manufacturers who design it. As and when new technologies are introduced one must be prepared to test it thoroughly so that the seemingly small mistakes do not cause catastrophic problems. When a Fly-By-Wire system is being implemented there are many unique testing and engineering considerations that need to be taken care of. Another difficulty with using software is that it could fail, no matter how many times it is tested - and the impact of such a failure would be massive. The challenge lies in designing hardware-software architecture for enhanced safety and reliability in a cost effective manner.

Sources:http://www.skybrary.aero/index.php/Fly-By-Wire http://www.ausairpower.net/AADR-FBW-CCV.html


Crashworthy car safety mechanisms

In this age of 24/7 living most of the people living outside this campus spend time travelling in their vehicles [except if the person

is jobless or a writer] caring less about their safety and more about the time left to reach their office/home which is right because they usually buy cars with safety features in it so that they don’t have to worry when they drive like a fool. So here is an exhaustive list of safety features which you should keep in mind in case you are lobbying for your own car with your dad’s money. If you will be buying with your own money then don’t read this. The following technologies would be ancient by the time you save enough money to buy your own car.

The shebang`

Seatbelts

Air Bags

ABSAn anti-lock braking system is a safety system that allows the wheels on a motor vehicle to continue interacting(through traction) with the road surface as directed by driver steering inputs while braking, preventing the wheels from locking up (that is, ceasing rotation) and therefore avoiding skidding.

Windshield GlassPlastic glass (layer of plastic sandwiched between glass, doesn’t break on impact), tempered glass (thermally

treated glass; breaks into small pebbles which are less likely to cause injury.)

4 Wheel DriveIt helps distribute power. Safe for off road travel.

Emergency Response SystemsWhen drivers of ERS-equipped vehicles get in a crash, the car company operators instantly know about the incident and the location because of built-in GPS technology.

Rearview CamerasSome of the first rearview sensors and cameras were introduced in the 1970s to help

enormous construction vehicles see what was behind them. The technology then caught on with automakers, who realized that it could be incorporated into regular passenger vehicles. In recent years, many carmakers have begun offering rearview cameras on new cars. Not all rearview cameras are the same. Most screens are located in the center of the dashboard, beneath the stereo controls, but some are actually mounted in the rearview mirror. Some rearview-camera systems also come with sensors that tell you when you're about to back into something -- particularly useful when parallel parking.

-NIPUN SAREEN


`Pre crash collision systems Although all drivers like to think they're in complete control at all times, sometimes it can be nice to have a little warning before we run into the car in front of us. After all, this is the age of cell phones, texting and myriad gadgets to distract drivers from the task at hand. There are different types of pre-crash systems; some actually compress the brakes when it looks like the car is about to be involved in a collision, while others simply alert the driver to the threat. Pre-crash collision systems use radar detectors that are placed in the front of the car. They detect the speed and distance between cars and let the driver know when there are sudden changes in the path directly in front of the vehicle. When the pre-crash system determines that a crash is likely, some newer models will hit the brakes for you. Other pre-crash systems automatically tighten the seatbelts and raise the seats. But of course, if you stay far enough from the cars in front of you, you'll never even know the system is there.

Blind spot detectionMost cars and trucks have a "blind spot," which is an area behind and next to the car that can't be seen in the mirrors. Thousands of accidents occur each year when drivers change lanes and collide with vehicles that are in their blind spot; many of those accidents can potentially be prevented with new blind-spot detection technology, which is alternately known as lane-change assist. Cameras and radar sensors are used to

monitor the space behind and alongside the moving car, and if they detect another car within your blind spot, a small warning light on your rear-view mirror will illuminate, alerting you to the presence of the other car.

Back Up Sensing SystemA proximity sensor in the rear portion of the vehicle senses when the vehicle gets too close to an object and warns the driver. This feature is an option on many mini-vans and larger sized SUVs.

Electro chromatic Mirror/Auto Dimming MirrorsThese mirrors automatically darken to reduce glare from the headlamps of vehicles approaching from the rear. The brighter the glare, the darker the mirrors become, making nighttime driving safer.

Energy-Absorbing Steering SystemThe steering column is made to compress upon impact, preventing rib fractures. Risk of driver fatality has been reduced 12% due to this benefit, and serious injury and death risks have been lowered by as much as 38%.

Head RestraintsRestraints on the top of front, outer seats reduce the potential for whiplash and other neck injuries in rear-end collisions. More advanced systems allow the back of the seat and headrest to move down and back upon a rear impact, lessening the forward motion and cutting down on head and neck injuries.

Heads Up Display (HUD) The head-up display projects speed and other information onto the windshield in front of the driver's eyes allowing the driver to maintain view of the road.

Impact Absorbing Interior MaterialsImpact absorbing interior materials provide padding and cushioning on dashboards and armrests to cut down on the bumps and bruises caused by crashes.

Padded Knee BolsterThe knee bolster works, in combination with the air bag and safety-belt-restraint system, to keep occupants carefully positioned for minimizing the stress on their bodies. Additionally, this feature helps prevent occupants from going beneath the instrument panel.

Tire pressure sensorsSince a high number of automobile accidents are caused by poorly inflated or punctured tires, one of the top safety devices of this decade is the on-board tire pressure sensor system. This system alerts a driver when there is a problem so they can seek immediate resolution. Some vehicles even come equipped with automatically inflating tires which will remain inflated long enough to help the vehicle pull over safely for inspection and repair. This safety device can and will prevent many unexpected tire “blow-outs” that are the cause of numerous accidents.

Adaptive cruise control The cars of this decade have been designed to “learn” our


`driving habits so that they can respond effectively to our needs, instead of the older clunkier push button styles of cruise control. This means a car’s response time when a sudden stop is required, is better. It’s also much less likely that the car will speed up erratically when ‘resume’ is pressed.

GPS SystemsSure, it’s important to be able to find specific addresses while traveling and that’s why so many people purchase GPS devices for their vehicles. Essentially, a GPS unit is great for saving on fuel, and locating services and addresses quickly without having to fumble for a paper map while driving. However, one of the neatest features of the GPS system today is that if you get lost while traveling in your vehicle or you break down on a deserted back road in the middle of the night, someone can find you. Now isn’t that safety at your fingertips?

Dual Airbags With Passenger SensorsAirbags save lives. Newer vehicles manufactured in this decade also include airbags to keep passengers safe, and manufacturers have taken it one step further by adding seat sensors to inflating when small children are in the car seats. So the airbags of today are drastically more effective at saving lives.

Headlight Advancements. It pays to be able to see well at night, especially in poor weather. The headlights of today’s automobiles provide much better light that promotes

clearer night vision. These vehicles result in fewer glares to oncoming drivers. Some cars are even equipped with smart headlights that not only turn on when it gets dark, but they change direction to avoid shining in the eyes of others when passing.

Wake Up Warnings. People today often drive exhausted, due to numerous economic and social factors. That means many people fall asleep at the wheel causing horrific accidents. For-tunately, an innovative wake up warning system has been designed to alert drivers with loud alarms, when they nod off, thereby preventing these types of accidents from occurring.

Electronic Stability Programme (ESP)ESP detects sudden changes in steering and braking, helping to prevent loss of direction and control of the vehicle. It reacts automatically when needed, ap-plying the necessary power and braking adjustments to individ-ual wheels, which helps reduce stopping distances in an emer-gency. This technology is avail-able as an option on all Ford Fu-sion models.

Electronic Brake-force Distribution (EBD)For stable braking and shorter stopping distances, EBD balanc-es the braking force indepen-dently across all four wheels.

Honda's Collision Mitigation Braking System works by moni-toring the distance and clos-ing rate between the Honda Civic and the vehicle in front. If a collision is likely to hap-pen, the driver will be warned, if an impact does occur, the impact will be reduced by the system by automatically assist-ing with heavy braking. The seatbelts will also be tightened in order to reduce loading on the driver during an accident.

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.


`

Driving along the N90 Route de Mons from

E s t i n n e s - a u - M o n t that connects the Bel-gian towns of Binche and Mons, several el-egantly shaped towers with blades mounted on them can be seen rising high above the elevated plateau.

These are 200 metres high wind turbines. A wind farm has been built by Belgian developer Wind Vision near the town of Estinnes which has the world's largest onshore wind turbines, 11 of the latest Enercon E-126 direct-drive wind turbines.

An Elephantine Turbine

The Enercon E-126 is the largest turbine model which has been built by German wind turbine giant ‘Enercon’. With a hub height of 135 m (443 ft), rotor diameter of 126 m (413 ft) and a total height of 198 m (650 ft), this gigantic turbine can generate up to 7.58 Megawatts of power per turbine. To give you all an idea, it must be asserted that you can run around 5,000 households of four in Europe with that amount of power. The weight of the foundation of the turbine tower is about 2,500 tonnes, the tower itself 2,800 tonnes, the machine housing 128 tonnes, the generator 220 tonnes, the rotor (including the blade) 364 tonnes rendering total weight to be about 6,000 tonnes.

The Highlights

These turbines are equipped with a number of new features: an optimized blade design with a spoiler extending down to the hub, and a pre-

cast concrete base. Due to the elevated hub height and the new blade profile, the performance of the E-126 is expected to by far surpass that of its predecessors.

The E-126 has no gearbox attaching the turbine blades to the generator, in fact, the generator is housed just at the widest part of the nose cone, it takes up the entire width of the nacelle to generate power more efficiently, and provide longer service life with less wear. Like small turbines, these have inverters instead of synchronous generators, that is to say, a separate controller that converts the wild AC generated into something the grid can use. This means the rotor can run at more optimum and varied speeds.

Moreover, this one does not shut right off at a predetermined speed due to gusts or just very high wind speeds. It simply throttles down by turning the blades slightly away from the wind so as to continue to generate power though at a lower production rate and the instant the wind is more favourable, it starts to back up again. Many smaller wind turbines do something similar except have no blade pitch control, they use a technique called something like “side furling” where the whole machine, excepting the tail, turns “sideways” to catch less wind but continue operating.

ENERCON E - 126

-NAVDEEP SHARMA


`

With the environmentalists constantly reminding us, it is easy to see that the road we are going down is not going to end well for our species. The conventional fuels are fast depleting and we need some cleaner alternates. With one turbine having the ability to supply power which can suffice the requirements of 1776 American homes, E-126 is indeed a credible answer to our woes. Further, these big things come cheaper in per unit production hence installation of one E-126 requires less financial commitment than three smaller turbines with 2MW power capacity. It also does not disappoint the environmentalist as the E-126 concept does not involve use of

permanent magnets and in designs so far doesn’t need any Neodymium, thereby avoiding the bad environmental imprint of rare earth mining.

However there was an issue of harming the local bird population which has been resolved by the newer designs which are bird friendly.

Technological advancements in the field of wind power have been made and will continue. At present E-126 is the largest and the latest but as Norway is currently (as of February 2010) working on building the World’s largest wind turbine a towering 10 MW machine, the quest for amelioration seems unending.

?1.Here are three answers: Answer A Answer A or B Answer B or C What is the correct answer?

AIN TEASERS?B

2. What is higher without a head than with a head?

3. How far can a dog run into the forest?

4. What is represented by this BrainBat? C CAVE

5. What is represented by this BrainBat? soiudte

6. What is the represented word or phrase?

Answers on Page 16

The Future


Intern Diary


`

Have you ever wondered how when we put on a pair of ordinary looking glasses,

Kungfu-Panda jumps to life in front of our eyes rather than looking like just a blur and blob of an awful colour scheme on the screen? The principles of 3D Technology have been oblivious to the human mind for many decades, although the technology has been existent since the early 1950’s.

In 1838, Sir Charles Wheatstone first described the process of stereopsis: the process by which humans perceive three dimensions from two highly similar, overlaid images. The human eyes are a mere 50 to 75 mm apart - this leads to the fact that the parts of the world perceived by both eyes are different even if they are focused on the same object. The single human eye is unable to perceive depth with great precision; it is with only a pair of eyes that the depth of an object can be ascertained with a high degree of accuracy. The disparity in the two images perceived by the eyes allows the human brain to calculate angles and analyze complex geometry that successfully creates the illusion of depth. However the difficulty arises when one tries to create the same effect using cameras trying not to butcher the whole effect. There are two ways in which 3D might be achieved at a cinema hall - polarized glasses and anaglyph.Anaglyph works on the basic principle of complementary and supplementary colours. The classic red and blue glasses which were used in the 1900’s build upon the stereoscopic method. In an anaglyph, the two images are superimposed in an additive light setting through two filters, one red and one cyan. Glasses with colored filters in each eye separate the appropriate images by

canceling the filter color out and rendering the complementary color black. Because of this additive or subtractive light setting each eye is able to get a different perspective and the brain is able to create the 3D effect. Polarized glasses or polarizers which are most widely used exploit the fact that light can

be polarized in many directions. Two images that are polarized in different planes are projected onto the screen and superposed to create the illusion of 3D. Since each filter lets through only that light which is

similarly polarized and blocks the light polarized differently, each eye sees a different image. Earlier horizontal and vertical polarization was used to create this effect - but one of the major drawbacks of this technology was that the head of the viewer should be still at all points of time due to the interference of waves when the head is slightly titled. However modern 3D technology conquered this problem with the use of spin polarization (clockwise or anticlockwise). Other technologies such as the eclipse method, Pulfrich method, spectral separation and interference filter technology may also be employed to create a 3D image. The eclipse method uses a mechanical shutter to completely block the light entering one of the

-VIBHOR KALRA


`eyes for a short duration of time. This shutter alternates between the two eyes at a very high rate giving the illusion of 3D. The shutter alternating rate is far greater than the refresh rate of the images on the screen. This method is also suitable for bringing 3D home. To obtain a 3D image we need two images from the same perspectives as if a pair of human eyes is viewing the scene. A regular motion picture camera records the images from two perspectives, however today most of them are computer generated through the post production phase.

Filmmakers need to triangulate the position of both the cameras and the object and make sure that they are focused on the object at all times.

They also need to zoom, track and move at the same speed otherwise the images are out of sync. To counter some of the complexities involved in this method, filmmakers today use mirror rigs. Mirror rigs film through a single lens and then bounce the image back to another lens using a mirror. 3D technology has truly come a long way since its conception in 1838 and has yet a long way to go.


`

iron man Technology

We are talking about a fictional character who is a scientific genius, not the stereotyped nerd but a charismatic and charming

personality. We are talking about the brainchild of Stan Lee, the writer-editor of Marvel comics who uses futuristic technology to create a suit which is capable of withstanding the brunt of bullets and missiles and accomplishing long flights with advanced flight control and safety. Yes, we are talking about the Ironman. Apart from two multimillion dollar bock busters, this character has inspired the scientific community too. So let’s look at some of them and see how close we have come to them in the real world.

Quite frankly, we are not at the stage to replicate the interface between Robert Downey Junior and his computer as in the movie, but research is being done on bits and pieces from it.For example, The Graphics Lab at the University of Southern California has designed an easily reproducible, low-cost 3D display system. The system works by projecting high-speed video onto a rapidly spinning mirror. As the mirror turns, it reflects a different and accurate image to each potential viewer. They used an anisotropic spinning mirror to reflect light according to an algorithm they have written to replicate the 3D object. Also not having parallax error adds to a feature that multiple viewers can see this image from different angles to get different perspectives of the image.

Cybernetic Interface

-VAMSHI KRISHNA


`

`Gesture recognition & control

Wired gloves:(Minority Report anyone??) These can provide input to the computer about the position and rotation of the hands using magnetic or inertial tracking devices. DataGlove is one such device already in the market. They can detect hand position, movement and finger bending. Furthermore, haptic feedback to the user can also be given in some cases, which is a simulation of the sense of touch. These devices use fiber optic cables running down the back of the hand. Light pulses are created and when the fingers are bent, light leaks through small cracks and the loss is registered, giving an approximation of the hand pose.

Depth-aware cameras. Using specialized cameras such as time-of-flight cameras, one can generate a depth map of what is being seen through the camera at a short range, and use this data to approximate a 3d representation of what is being seen. These can be effective for detection of hand gestures due to their short range capabilities.

Controller-based gestures. These controllers act as an extension of the body so that when gestures are performed, some of

their motion can be conveniently captured by software as is the Wii Remote, which can study changes in acceleration using an accelerometer to represent gestures.

Creating a new element altogether in his home by building a particle accelerator in his home: Too far dude, too far.

Apart from all the hard work and the mind crunching brainstorming in science, human imagination also seems to play a crucial role in the advancement in science and technology. So maybe it is not that bad an idea to let our imagination run wild once in a while eh?

Move over, Iron Man

These suits of armor or robotic exoskeletons are in existence now, designed by Raytheon for the military to increase the strength, endurance and agility of soldiers in combat.

The 150-pound exoskeletons are made of sensors, actuators and controllers and increase a person’s strength and endurance by as much as 20 times. XOS 2,

essentially a wearable robotics

suit was unveiled for the first time in September 2010 at the company’s Salt Lake City research facility.

The XOS 2 does the lifting for its operator, reducing both strain and exertion. It also does the work faster. One operator in an exoskeleton suit can do the work of two to three soldiers. The suit is built from a combination of structures, sensors, actuators and controllers, and it is powered by high pressure hydraulics.


`

ENTROPoutside the books

It was not easy for a person brought up in the ways of classical thermodynamics to come around to the idea that gain of entropy

eventually is nothing more or less than loss of information.

When Rudolf Claussius proposed his famous “statement” wherein he stated that not all the energy that you get from heat can be converted to work, and that the first law alone cannot completely define a system, he was set to change the way the world looked at Thermodynamics forever. And the reason Entropy is discussed so much - one of the reasons it ended up as the subject of my article in fact - is because of its multifaceted applications in fields totally unrelated to Thermodynamics.

EvolutionEvolution involves two main processes – the

random mutation of genes from the millions of possible permutations and combinations, and natural selection – where the stronger and fitter variants of the above mutations tend to populate the species more than the others and have more reproductive success- i.e. their birth rates increase and their death rates decrease. Now, though this seems like a process in which entropy decreases – because a certain sect of the species is chosen from a large sample space of various variants, and hence the result becomes less random and more organized than the original set of species – it isn’t, and evolution is very much in line with the Second law of Thermodynamics. Now, the second law says that a system consisting

of irreversible processes always has increasing Entropy. And this is the very reason Evolution ends up being a process in which entropy finally increases. Birth, death, gene mutation are all in general, considered to be irreversible processes –

because if we consider the alternative i.e. that all these processes were completely reversible, then the birth of species selected by natural selection could be reversed (negating their existence) and the death of those species which were considered “unfit” could be reversed – which would cause the “unfit” “un-dead” species to continue to live in the population and the “fit” unborn species to be absent from it. This directly contradicts the purpose of evolution, as ultimately we end up with the same sample space we started off with as no change/mutation in the gene pool for the good or for the better would prevail. Thus, since the process of Evolution consists of millions of irreversible processes it must be a process with increasing Entropy – thus not violating the Second Law of Thermodynamics.

In daily life

Statistical mechanics tells us that the Entropy of a system is related to the randomness, or the uncertainty of the system as a whole. We also know that higher the entropy of a system lower the amount of sensible energy we can get from the system and lower the efficiency. A system which is capable of giving a large amount of energy that is highly disordered (i.e. high entropy) might not be as useful as a system that gives us a small amount of easily harness-able (low entropy) energy. It is surprising how ubiquitous this concept of quality versus quantity is in our life. Take two companies with car factories – A and B, say.

“Nothing in life is certain except death, taxes and the second law of thermodynamics.”

-N R SREERAM


`Both have the exact same capacity, workforce, funds – the only difference in their setups is that factory A is more organized and has better interaction among the workers than B. Now, the first law efficiencies of the two factories are the same. i.e. the both have the same static and boundary conditions – and hence must be equally productive. But, as we know, the first law itself does not tell us the complete story - factory A being more organized, would be much more efficient than B. The analogies are obvious – B has more entropy than A and hence more internal irreversibilities (i.e. time and energy lost in confusion and disorganization among the workers) than A which is more organized and streamlined in its operation.

Such examples abound around us in life. Take two libraries of thousands of books each, for instance. Finding a book (i.e. useful work) is easier in the one which is more organized (one with less entropy) the one in which they are arranged haphazardly. Even we humans are beings who are more productive in organized environments. Disciplined and organized habits are usually conducive to more productive results. The very concept of settlements – villages, cities, townships – stems from the fact that a collective and organized group of people living together (concentrated energy – less entropy) is better

than hundreds of small groups of humans living like nomads with no order or discipline (unorganized, high-entropy energy) in the long run – a fact history has proven over and over again through the ages.

But let’s take a moment to think a little differently here – of life as more of a journey than just a list of tasks to be completed according to a strict schedule. Where would we be without a little truancy – a little bit of veering off from the path oft-traversed? Serendipity plays a very important role in shaping our lives as humans. Things that happen to us when we are least expecting them to leave a greater and deeper impression on our minds than the ones that are pre-planned. Hand on heart, how many of your most memorable moments happened after intensive planning and scheduling? And how many of them happened over impulsive decisions taken by a group of friends at a lunch table? And more often than not, the best decisions taken by us turn out to be spontaneous ones taken without much deliberation. I am in no way suggesting that we should take life as it comes with absolutely no groundwork or preparation and be impulsive about everything we do - it is just a question of finding that sweet spot between being mindless, mechanical beings and chaotic, restless and unruly animals.

AUTO CROSS SOLUTION


Intern Diary


Let us think about how our ancestors used to measure time around 1000 A.D. What can we think of? Generally we get stuck with two options which

we know as some of the oldest time measuring devices, the Sun Dial and the Sand Dial. Let us talk about the sundial first. Someone might think what would happen during rainy season, the sun dial would not work then for most of the time. Next comes the sand dial, which most of us would have seen in old Arabic themed movies or for gamers, in ‘The Prince of Persia’.

`

L'arte della meccanica

But Sand Dial is like a temporary time measurement device. We have to invert it to extend its time length. Besides in that time we had a hindrance to automation of time unlike now ,when we have the modern clocks or watches. Just a small cell battery powers the watch for nearly 2 years. “ Ha Ha Ha” (haughty laughter and associated gestures), we think that we are very clever than our ancestors. But they were not dumb. There are some ancient inventions which are not that famous but can be said to be the Art of Mechanics ( the same thing written in Italian as the Title ). One of such finest pieces of Mechanical art is the Elephant Clock made by Al-Jazari (1136–1206), one of the geniuses in Mechanical engineering during the middle ages.The middle ages were considered to be the golden age of Islamic Civilization and Al-Jazari was considered to be one of the masterminds of that age. How did he incorporate hyraulics to time measurement as in the case of the elephant clock (which is a type of water clock)? One might think he simply used a tank from where water is drained, the water drained acts as a pivot to some mechanism showing us time on some scale. But if it was that simple I wouldn’t have called it an art. If you really see it like a mechanical engineer does, you would definitely think, “Man I have to build something like this in my life”. The various elements of the clock are put together in a housing on top of an elephant. They are designed to move and make a sound at each half

hour. A modern full-size working reproduction can be found as a centrepiece in the Ibn Battuta Mall, a shopping mall in Dubai, United Arab Emirates. Another working reproduction can be seen outside the Musée d'Horlogerie du Locle,

Château des Monts, in Le Locle, Switzerland.Mechanism: The timing mechanism is based on a water-filled bucket hidden inside the elephant. In the bucket is a deep bowl floating in the water, but with a small hole in the centre. The bowl takes half an hour to fill through this hole. In the process of

-VIVEK CHOWDHARY


`sinking, the bowl pulls a string attached to a see-saw mechanism in the tower on top of the elephant. This releases a ball that drops into the

mouth of a Serpent, causing the serpent to tip forward, which pulls the sunken bowl out of the water via strings. At the same time, a system of strings causes a figure in the tower to raise either the left or right hand and the mahout (elephant driver at the front) to hit a drum. This indicates a half or full hour. Next the snake tips back. The cycle then repeats, as long as balls remain in the upper reservoir to power the emptying of the bowl.Automation:In the mechanism, a humanoid automaton strikes the cymbal and a mechanical bird chirps, like in the later cuckoo clock, after every hour or half hour.Passage of Temporal hours:Another innovative feature of the clock was how it recorded the passage of temporal hours, which meant that the rate of flow had to be changed daily to match the uneven length of days throughout the year. To accomplish this, the clock had two tanks, the top tank was connected to the time-indicating mechanisms and the bottom

was connected to the flow control regulator. At daybreak the tap was opened and water flowed from the top tank to the bottom tank via a float regulator that maintained a constant pressure in the receiving tank.

Flow Regulator:The mechanism employed a flow regulator, which was used here to determine the time when the clock strikes at hourly intervals. The hourly intervals were determined with the use of a small opening in a submersible float, which was calibrated to give the required rates of flow under different water rates. The float regulator was later a common mechanism during the Industrial Revolution of the 18th century, when it was employed in the boiler of a steam engine and in domestic water distribution systems.Closed Loop System:This appears to be an early example of a closed-loop system in a mechanism. The clock functioned as long as there were metal balls in its magazine.Cultural Significance:Apart from its mechanical and engineering innovations, the clock itself is seen as an early example of multiculturalism represented in technology. The elephant represents the Indian and African cultures, the dragon represents Chinese culture, the phoenix represents ancient Egyptian culture, the water work represents ancient Greek culture, and the turban represents Islamic culture.Reading all this we can definitely say that innovation and creativity is timeless. Belonging to that time it is truly an amazing work of art and mechanics. This medieval area of study is famously known as science of tricks. So, as present generation tricksters are we not interested in creating such masterpieces? Definitely, we are.

?7. A man wants to take a 1.25 meter-long rolled up painting onto a train, but the conductor won’t permit items whose greatest dimensions exceeds 1 meter. What should he do?

Answer on Page 16


ANIMAL ROBOTS

Ever wondered how nature can be helpful to solve our problems? Man has a long history of seeking solutions from nature.

Looking back at past, there are innumerous examples of great minds getting inspired by the nature.

Whether it was fascination to fly like bird, to see in dark like bats or the invention of Velcro, which was inspired by the tiny hooks found on the surface of burs, all have contributed towards the better tomorrow. Something is peculiar about the above solutions, yes, they all derived from nature. The field of Bio mimicry is defined as the examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems. These problems may be simple like to fasten up your sneakers or as complex as designing the efficient solar panels. Since Mother Nature has always helped us to progress ahead with time, she also has provided a “readymade solution” to most of our problems.The “Animal” robotics is a sub division belonging to the broad scope of bio-mimicry. Since in bio-mimicry the solutions are inspired by the Mother Nature, similarly these bots are made to imitate the traits of real animal. These bots find wide application in military, search and rescue operations, chase & evade, etc.

As we know that the cheetah is the fastest land animal, and so does the Defense Advance Research Project Agency (DARPA) of USA which has conceptualized the Cheetah bot. Boston Dynamics, maker of BigDog, is awarded to build this furious cheetah. Since most of the humanoid robots move creepily, the four legged is designed to be faster and agile enough to chase and evade any human

prey. The m a i n feature of c h e e t a h bot is its u n i q u e ability to move in z i g z a g f a s h i o n to chase and evade. Its makers are also eying for a role in emergency response, firefighting, advanced agriculture and vehicular travel.

The goal of the project is to develop a robot capable of running on water, without any floatation, modeled after the Basiliscus basiliscus(Jesus L i z a r d ) . The basic principle of this seemingly s u p e r n at u ra l power is the Newton’s third law of motion. So, if you could displace the water at rate which is just sufficient to balance your weight then you too can walk on water. The weight is also supported by surface tension of water. At present a computer model

CHEETAH BOT

JESUS LIZARD

-ABHINAV YADAV


`of the forces experienced by a four legged robot running on the surface of the water has been developed and used to create different leg designs for testing purposes. From this iterative design approach, body parts have been rapid prototyped for scale model testing. Possible improvements over nature have presented themselves, and are being built to determine model accuracy. Once completed, this too will have applications in military and search & rescue operation.

These bugs actually work on “swarm intelligence” principle. Swarm intelligence means several individual entities operating as a single entity to accomplish a job. Similarly, here also many bugs will communicate with each other transferring the information about their immediate surroundings. They are small enough to mount on the fingertip and weigh less than 30 grams.

Owing to their small size, they can easily move through the wreckage of building collapsed in an earthquake. Thus, they can prove to be very vital in the post disaster relief operations. Many Armies are also using these types of bots for spying and surveillance. Currently, British and American military manufacturers have produced the prototypes and are mulling over the artificial intelligence of these bots. This is just the beginning. In virtue of their wide range applications and impressive abilities the animal robots are going to be evolved into more

and more sophisticated forms.

This bot find its correct place for spying and military vigilance. It has been fabricated to give it a perfect look of real serpent. It is appropriate for underwater operations also. According to DARPA its body is adaptable for wide range of

task like climbing tree, overcoming obstacles, crossing slippery surfaces and sensing immediate surroundings. Till now many manufacturers from countries like U.S, Israel, Japan, etc. have come up with their prototypes and are looking forward to improve their design.

This bot is inspired by gecko lizard which is capable of climbing walls. It uses the pressure sensitive adhesive to get stuck on the wall. It is able to climb any type of wall may it be rough, dry or even wet. A proof of concept robot has been f a b r i c a t e d and climbed 60 degrees. Improvements are underway. Having the aforementioned abilities it is bound to be used for spying and surveillance.

ROBOTIC BUGS

SNAKE BOT

GECKO BOT


`

TRAINING THEBRAHMAPUTRA

The Brahma Purana hails Brahma as ‘the creator’. In the Hindu mythology he is regarded as one of the Trimurti along with

Vishnu and Shiva. In our country, where most of the rivers are conferred with feminine appellations, we have a rare male title on the list: the ‘Brahmaputra’ which literally translates to son of Brahma.

“But one should not forget that the river originates in Jima Yangzong glacier near Mount Kailash, the abode of Lord Shiva. Lord Shiva, the destroyer.”

With an average discharge of 19,300 cubic meters per second (nearly twice that of the Ganges), the river lives up to its imposing name by fostering life and prosperity in the region. Like father like son, one would say. However, in the summer months, the snow starts melting in the Himalayas and by June the monsoon rains also join in to play their mighty hand in augmenting the average flow rate to as large as 100,000 cubic meters per second and the Brahmaputra, the symbol of prosperity and creation starts eroding and engulfing fertile soil, crops, and sometimes life and property as it assumes destructive overtones.

The Mighty Problem

It is evident that the state of Assam has lost a considerable share of prime land due to the notorious nature of the river. Being elephantine in its size, the river carries a huge amount of sediment load (about 800 million tonnes). As the flood recedes, most of this sediment gets deposited in the river bed and the banks rendering the fertile cultivable land unsuitable for crop production. In addition to this, it is a classic example of a ‘braided river’ and hence is susceptible to channel migration and avulsion. In simple words one can say that the sand deposits create multiple channels in the river thereby reducing its velocity. Brahmaputra hence is a river of heavy sediment load with a low hydraulic efficiency, and a nightmare for engineers.

Taming: Banking on the Brahmaputra

The existing structural measures for river training in India include building of embankments and setting up of spurs to prevent flooding in low lying areas. Such an embankment designed to establish control over the flow is called a levee. These techniques have been there in India for many years. The earliest evidence of embankments in the subcontinent dates back to the Sultani period (1213 AD- 1519 AD) when Sultan Ghiyasuddin Iwaz Khilji had built a series of embankments to prevent his capital Lakhnauti from floods. The Grand Trunk Road also had flood control applications. The Mughal emperors also

constructed many structures to tame some large rivers. There can be many kinds of structures namely longitudinal constructions, revetments

-NITIN KHOLA


`and weirs. The most common solution are the longitudinal constructions which are structures designed with their length parallel to the direction of river flow.For decades, the Central and State governments have made efforts to restrain the untamable Brahmaputra by building 5027 km of embankments on the river and its tributaries. The embankments did achieve the purpose of preventing the flooding of banks for a few years. But the solution turned out to be a myopic one. As told before, the river carries a heavy sediment load and construction of embankments led to confinement of the sediment between the

embankments thereby raising the riverbed level. Therefore at the time of breaches the water brims over the embankments and deposits heavy amount of silt on the fertile cropland. Besides, embankments and other existing techniques are capital intensive with high maintenance cost. Hence experts suggest that instead of taming the Brahmaputra, we should strive to train it.

Training: Submerged Vanes, Jack and Jetty

Submerged vanes are placed longitudinally on the riverbed in an array with predetermined spacing. They are made of steel plates, reinforced cement concrete (RCC) slabs, wooden planks or bamboo poles. The principle behind the design of vanes is to generate secondary flow spirals, which induce sedimentation on one side of the vanes and deepen the riverbed on the other side. The vanes are placed in a manner such that a relatively small number of them can produce bend flows which are practically uniform across

the channel. The vane system helps in reduction of near bank depth and velocity of flow thereby preventing banks from getting undermined and eroded. A jack is another flow control device which can help in saving banks from lateral erosion. The standard design has six rigidly fixed arms fixed at the center which helps in breaking up the erosive flow of vortices. The most widely used jacks are: Steel jacks that are strung with wire, Kellner jacks which are made of three steel struts and Concrete jacks which comprise of three beams joined at the midpoints. Generally rows of jacks are placed parallel to the banks outside or inside the channel; these rows are called jack fields.River jetties or groynes are structures or piers of stones or substitutes which protrude into the river bed and serve the purpose of moving the flow away from the side of the river on which they are built. They are often constructed

nearly perpendicular to river banks and help in controlling lateral erosion, scour and shoaling. The solutions discussed above are the most widely used techniques which have been successfully implemented in various parts of the world. Along with these, many other techniques such as Board Fencing, Gabion Gravity Structures, and Reinforced Soil Structures have also catered to the objective of river training. With the traditional technique of embanking the Brahmaputra turning out to be a short term solution, there is a dire need of implementing the cost-effective and long term river training techniques of submerged vanes, jacks and jetties along both banks of the river in a sincere manner. Then we would be able to ascertain that the mighty river continues to serve as a nurturer and not as a destroyer for the fertile croplands.


R̀eminiscence

Time flows like grains of sand,

Or, like the lash of a magic wand.

We sail through the vivid lands of the wild,

Lost in this world, we become the lonely child.

Class notes, lectures, labs, exams and PT,

Make life here totally different from city.

Late night movies take their toll,

Even you reject the poor alarm's call.

Internet and games create a spark,

They become for us a new hallmark.

Nothing seems important as Twitter or Facebook,

Until our life is on fire, we don't even open a book.

This precious life with our friends

Marks the beginning of new trends!

Trekking along the serpentine roads,

We carry on bearing academic loads.

We relish sports and celebrate festivals of all kind,

And co-curricular activities never leave our mind.

Time ebbs away but memories trail,

These feelings are no longer so frail.

The sweet days in college always entail,

As long as in this world we continue to sail.

-ANGSHUMAN


Auto Cross

Answer on Page 28

ACROSS DOWN

-AVINASH YADAV

39 Indian Institute of Technology, Guwahati 40 Indian Institute of Technology, Guwahati

40 Indian Institute of Technology, Guwahati

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