3
THE EEEA REVIEW
Designed by Harryarts -Freepik.com
Wishes You
4
THE EEEA REVIEW
Editors desk
6
Bendable-wearable Electronics
7
Tesla’s Ta’u island
8
Pocket sized printer
10
5 breakthrough technologies
11
Secretary
Emotion recognition using wireless
12
Divi Bharadwaj
Selfie drone
13
Editor Prateek Gulati
What happens inside a battery right before it explodes
14
Mind reading computers
15
Design
Digital Jewellery
16
Polyjet 3D printer
17
National technology : Year end review
18
The Enigmatic Rings
19
Black holes
20
Wireless Power Transfer
22
FLYTE - Flying Bulb
24
Decision Review System Taekwondo
26 27
Travel destination of this season
28
Living the American dream
30
CyanogenMod
31
Electrical engineer : things that we can fix
32
Imaging Solar Cells in 3D
33
Let’s Uncomplicate the Theory of music
34
EEEA CREATIVES
36
Highlights of the Month
39
President Dr. K. Vijayakumar
Kallol Chatterjee
Marketing and advertising T | +91 9176043185 eeea.srm@gmail.com
CONNECT WITH US https://www.facebook.com/eeeassociation.srm
https://www.instagram.com/eeeassociation/
Correspondents & Contributers Technical Dhruv Gupta Sneha Bhattacharya Vishal Sehgal
Abhishek Iyer Shweta kurian Pratyush Tripathi
Sports Nilesh ojha Cultural Shikhar Sahai Creatives Shalini Haldar
Anamika Ranjan Biswadeepa Bhattacharya
AS Pradeep Adhisha Raman Chidambaram rakkappan
Publicity Disha Roy
Soumyadip
Anubhav Pandey
Photography Sai Kaushal
Atri Kar
Soham Mandal
Documentation Sai varun Dheeraj
Strictly speaking, these pages will help you wrap your mind around some of the most important companies, technology and ideas of our time. Here in this issue you will find better wearable electronics, Tesla’s Ta’u island, pocket size printers,emotion recognition using wireless signals. There are articles based on sports, music, travel and photography in this issue as well. Lastly, we have got more number of reader submissions for articles in this issue, which is appreciated. I would like to encourage other readers to write and send their suggestions/articles or any other ideas to the association mail to help us become better. Give us a feedback!
HAPPY HOLIDAYS Prateek Gulati Technical Head, Editor in Chief the EEEA REVIEW
From the Editor 6
THE EEEA REVIEW
A new, ultrathin film that is both transparent and highly conductive to electric current has been produced by a cheap and simple method devised by an international team of nanomaterials researchers from the University of Illinois at Chicago and Korea University. The film is also bendable and stretchable, offering potential applications in roll-up touchscreen displays, wearable electronics, flexible solar cells and electronic skin. The new film is made of fused silver nanowires, and is produced by spraying the nanowire particles through a tiny jet nozzle at supersonic speed. The result is a film with nearly the electrical conductivity of silver-plate and the transparency of glass. The silver nanowire is a particle, but very long and thin. The nanowires measure about 20 microns long, so four laid end-to-end would span the width of a human hair. But their diameter is a thousand times smaller — and significantly smaller than the wavelength of visible light, which minimizes light scattering. The researchers suspended the nanowire particles in water and propelled them by air through a de Laval nozzle, which has the same geometry as a jet engine, but is only a few millimeters in diameter. The liquid needs to be atomized so it evaporates in flight. When the nanowires strike the surface they are being applied to at supersonic speed, they fuse together, as their kinetic energy is converted to heat. The ideal speed is 400 meters per second. If the energy is too high, say 600 meters per second, it cuts the wires. If too low, as at 200 meters per second, there’s not enough heat to fuse the wires. The researchers applied the nanowires to flexible plastic films and to three-dimensional objects. The surface shape doesn’t matter. The transparent flexible film can be bent repeatedly and stretched to seven times its original length and still work.
7
Left, photograph of a large-scale silver nanowire-coated flexible film. Right, silver nanowire particles viewed under the microscope. Credit: S.K. Yoon, Korea University
THE EEEA REVIEW
Tesla runs an e
on solar p Now that Tesla has officially acquired SolarCity, it's not wasting any time showing what the combined entity can do. Tesla has revealed that it's running the island of Ta'u (in American Samoa) on a solar energy microgrid that, at 1.4 megawatts, can cover "nearly 100 percent" of electrical needs. It's not just the 5,328 solar panels that are key -- it's the 60 Tesla Powerpacks that offer 6 megawatt-hours of energy storage. While Ta'u is normally very sunny, the packs can keep it running for three days without sunlight. They don't have to worry about a cloudy day leading to blackouts. The solar switch, which took a year to complete, has both its long-term environmental and immediate practical benefits. Like many remote communities, Ta'u previously had to run on diesel generators. That burns 300 gallons of fuel per day,
8
THE EEEA REVIEW
entire island
power
By AS Pradeep
which is neither eco-friendly nor cheap. Solar eliminates the pollution, of course, but it also saves the cost of having to continuously buy and ship barrels of diesel. And crucially, it provides a more reliable source of electricity. Locals previously had to ration power (say, if a diesel shipment wasn't on time) or accept periodic outages. Now, they can assume they'll have power at all times. Ta'u is clearly an ideal test case. On top of its paradise-like weather, there are less than 600 residents with relatively modest power needs. It'd require much, much more power to accommodate a full-blown city, especially in climates where cloudy days are more commonplace. However, it could still serve as a good example. Tesla's mission is to wean the world off of fossil fuels, and this shows that it's a realistic goal in at least some corners of the globe.
9
THE EEEA REVIEW
10
THE EEEA REVIEW
ExVive Human Kidney Tissue
ZipChip
ExVive Human Kidney Tissue from Organovo is a replica of the kidney proximal tube created using 3D bioprinting. It offers drug developers a reliable means of testing for renal toxicity. Currently, few preclinical tests can determine whether a potential drug is toxic in humans, making investing in clinical testing risky for developers. Bioprinting operates on a similar principle to 3D plastic printing, but instead of putting beads of polymer into a printer, Organovo put little aggregates of cells.
ZipChip is a microfluidic device that radically speeds up mass spectrometry, requires minimum sample volumes, and broadens the range of materials that a mass spectrometer can handle. The small box, less than a foot long, mounts directly onto a mass spec and works by processing samples through a microfluidic chip the size of a microscope slide. ZipChip uses capillary electrophoresis to separate sample components in just two to three minutes when liquid chromatography columns would require up to an hour. The device provides better separation for samples, such as proteins, antibodies, and antibodydrug conjugates that are difficult to separate with other techniques.
Reusable Rockets
DNA App Store
Thousands of rockets have flown into space, but not one did return like this: it came down upright on a landing pad, steadily firing to control its descent, almost as if a movie of its launch were being played backward. If this can be done regularly and rockets can be refuelled over and over, spaceflight could become a hundred times cheaper. Two tech billionaires made it happen. Jeff Bezos and Elon Musk.
An online store for information about your genes will make it cheap and easy to learn more about your health risks and predispositions. Helix’s idea is to collect a spit sample from anyone who buys a DNA app, sequence and analyze the customers’ genes, and then digitize the findings so they can be accessed by software developers who want to sell other apps.
a
Tesla Autopilot
11
The electric-vehicle maker sent its cars a software update that suddenly made autonomous driving a reality. It did in fact give drivers something similar to what airline pilots employ in flight. The car could manage its speed, steer within and even change lanes, and park itself. Some of these features, like automatic parallel parking, were already on offer from other car companies (including Mercedes, BMW, and General Motors), but the self-steering was suddenly, overnight, via a software update, a giant leap toward full autonomy.
THE EEEA REVIEW
Emotion Recognition Using Wireless Signals by Sneha Bhattacharya
Emotions can be tricky enough for humans to read, let alone machines, but a new system can predict people's feelings with 87 percent accuracy by bouncing wireless signals off them, researchers say.
After training on each subject individually, the system could accurately classify their emotional states 87 percent of the time. A separate system trained on data from 11 participants was able to classify the emotions of the unseen 12th subject 72.3 percent of the time.
Using a device smaller than a Wi-Fi router, researchers at MIT were able to monitor a person's breathing and heartbeat wirelessly. These measurements were then fed into a machine-learning algorithm that classified the subject’s emotion as excited, happy, angry or sad. The accuracy was similar to state-of-the-art wired approaches.
The system relies on a radar technique called Frequency Modulated Carrier Waves, which is particularly powerful because it can eliminate reflections from static objects and other humans, the researchers said. This high-precision body tracking is sensitive enough to pick up the rising and falling of the chest during breathing as well as minute vibrations caused by blood pulsing through the body. As heart contractions happen much faster than breathing acceleration, measurements are used to isolate the fainter heartbeat signals.
The setup, called EQ-Radio, analyses the signal reflected off a subject's body to monitor both breathing and heartbeat. These physiological cues are commonly used to detect a person's emotions, but it typically requires hooking up the subject to a host of sensors. The inventors say potential applications include health care systems that detect if you're getting depressed before you do, "smart" homes that can tune lighting and music to your mood or tools that allow filmmakers to get real-time feedback on their audience's reaction.
But Dina Katabi, a professor of electrical engineering and computer science at MIT, who led the research, is confident the device will hold up in real-life situations. She plans to incorporate the emotion-detection capability into devices made by her company Emerald that use wireless signals to detect falls among the elderly.
To test EQ-Radio, 12 subjects were monitored for 2 minutes at a time while experiencing no emotion and also while using videos or music to recall memories that evoked each of the four emotions (excited, happy, angry and sad). A machine-learning algorithm was then trained on each subject's heartbeat and breathing data from each monitoring period.
The researchers also think the fact that the system relies on mechanical signals rather than electrical ones to monitor the heart could lead to significant applications in health care. Guess, reading emotions and understanding each other is easy now.
The system intelligently combines the two and then maps the results onto a graph where one axis represents arousal and the other represents "valence" – essentially, whether an emotion is positive or negative. This is then used to classify the emotion into the four broad categories.
Click or scan the code to know more
12
THE EEEA REVIEW
The AirSelfie is the brainchild of Italian entrepreneur Eduardo Stroppiana, who came up with the idea in 2014. "AirSelfie is specifically designed and produced for people who used to think drone cameras are extremely complicated to use — too expensive and bulky," Stroppiana said. The AirSelfie is equipped with a 5-megapixel camera that can shoot full high-definition (HD) 1080p video, as well as a 4GB micro SD card. Using the AirSelfie, people, groups and companies can take pictures of themselves, their backgrounds and their projects from distances, heights and angles that they never could using their arms or a stick. The drone's four rotors help it fly up to 65 feet (20 meters) in the air. The flying camera measures only about 3.72 by 2.65 by 0.42 inches (9.45 by 6.73 by 1.07 centimetres) — "smaller than a smart phone," Stroppiana said — and weighs 1.83 ounces (52 grams). The drone uses sonar to measure its altitude and keeps itself stable with the help of a tiny extra camera to monitor its surroundings for signs of jitter. The AirSelfie is controlled via a free iOS or Android app. The app can make the drone
take off; adjust its height and direction; let it hover autonomously; and help users take an HD aerial shot or video with just a push of a button. Users can also activate a 10-second timer, giving people enough time to hide their phones so they don't appear in the picture or video. The drone can take up to eight consecutive shots, the company said. The AirSelfie uses Wi-Fi to send photos and videos wirelessly to smart phones. The app also allows users to post photos and videos taken with the drone immediately on social media. After snapping photos, the drone can return to its departure point automatically with the touch of a button. A rechargeable lithium polymer battery gives the AirSelfie a flight time of 3 minutes, according to the company. An accessory known as the Power Bank slips over the AirSelfie like a smart phone case, and can recharge the drone in 30 minutes. The Power Bank can hold 20 such charges before it needs to be recharged. The company said it developed a fully functioning prototype in August. The first preordered drones are scheduled for delivery in March. The drone is expected to hit the market in 2017 for a retail price of $300.
Selfie Drone Captures Photos and Videos in Midair by Vishal Sehgal 13
THE EEEA REVIEW
WHAT HAPPENS INSIDE A BATTERY RIGHT BEFORE IT EXPLODES by AS PRADEEP Overcharging or overworking deforms the insides of a battery.
From the fiery Note 7 debacles to exploding hoverboards, lithium-ion batteries aren't doing so hot lately. A new study helps to explain how these popular power sources can turn into safety hazards.
(A) shows the inside of a battery before it was misused. (B) shows how misuse causes the original design defects to become even more warped.
In the paper, published in the Journal of the Electrochemical Society, scientists at the Canadian Light Source (CLS) synchrotron looked inside an overworked battery. In this case, they drained a battery until its voltage was below a critical level.
(C) highlights the areas where warping got worse.
When we overcharge or overheat lithium ion batteries, the materials inside start to break down and produce bubbles of oxygen, carbon dioxide, and other gases. Pressure builds up, and the hot battery swells from a rectangle into a pillow shape. Sometimes the phone involved will operate afterwards. Other times it will die. And occasionally—kapow!
bubbles produced during overheating warped and dented this electrode. Intriguingly, the study authors found that the worst deformation from the gas buildup occurred in areas that had slight defects before the battery was ever overdrained. The authors note that doing more studies like this, on a larger variety of batteries, would improve understanding of how these batteries respond to gas evolution, which could lead to better designs.
To see what's happening inside the battery when it swells, the CLS team used an x-ray technique called computed tomography. Inside the battery is an electrode that spirals out from a central point like a jellyroll. The x-ray scan revealed that the
As New Scientist notes, it's not clear whether the Samsung Note 7 catastrophes included pillowing or this type of deformation.
Source: 1. www.popsci.com 2. Journal of the Electrochemical Society via New Scientist
14
THE EEEA REVIEW
Shweta
If you have watched Blade Runner in which artificial human adults called "replicants" come to Earth. As replicants are not allowed on Earth anymore after some of them had attacked humans, police officers called "Blade Runners" hunt down and kill them on Earth. Rick Deckard is forced to hunt down some replicants in Los Angeles. The first generation of computers made by man cost around millions and millions of dollars and were kept in closed rooms with special electrical circuits and cooling systems. The only people who were authorised to use these computers had been trained to write programs in that computer’s jargon. Fast-forward to today, and we have gesturebased interactions, using multi-touch pads and touch screens, and exploring our virtual 3D spaces helps us interact with devices in ways very similar to how we deal with actual physical objects. Research hopes to develop the next phase of human-computer interaction. It has enabled us to currently monitor people’s brain activity in real time and even recognise specific thoughts in human beings. After years of research, man has made simpler tools to become commercially available for users. As opposed to the early 1990's where the programmers could help build 2D and 3D digital models and add colour, movement and interaction, in recent years, 3D displays have become much smaller and cheaper. They needed space 30 ft wide, 30 ft long and 20ft high, now smart phone holders provide personal 3D display for less than 100 dollars. A few years from now, hardware/software systems using neuroheadsets could replay topics of recent thoughts, and humans could retrace their steps and remember what thoughts triggered their most recent thoughts. Once human thought can communicate directly with computers, it will open a whole new world before us. It could not only be applied to play games with more clarity in the
virtual word, it also could help write such games and develop the characters of the game using enhanced software platforms such as Versu. This kind of creativity could lead us to much more complex projects, all conceived in the creator’s minds and made into virtual experiences. Eventually we could add avatars with whom users can converse. As technology continues to progress and become easier to use, modelling clay and twigs by children 50 years ago could one day become explorable, life-sized virtual spaces. Now the question of these robots being under or not under our control in future, only time will be able to tell.
15
THE EEEA REVIEW
Technology is advancing day by day. Each day many gadgets tend to get smaller and more convenient to use. The humongous super computers we used to have back then have been replaced by small microprocessors. We’ve got everything in our hands but have you ever wondered what it would be like to wear your computer? Well that’s what digital jewellery is all about. As obvious as it sounds digital jewellery is basically jewellery but its digital i.e. jewellery with embedded intelligence. Yes that’s right! But why do we have digital jewellery? That’s because we are driven by the need to make things more compact and easy. Digital jewellery is used to do numerous things like remembering passwords, managing user accounts, controlling your computer, switching room lights and so on. Rings, bracelets, necklaces and earrings have been used as digital jewellery so far.
notify the user about an incoming text or call. Bracelets and watches on the other hand act as display devices. They may consist of a 7-16 segment, or dot matrix LEDs and LCDs .They display text messages and other data. Now how cool is it for you to make gestures by your hand using the ring and the required action to happen like sending a message using your fingers. Sounds like the gadgets Bond could use doesn’t it? Many prototypes and products have already come up like the Garnet ring and the Java ring first introduced at Java one conference. Digital jewellery does come with its pros and cons. The pros have already been mentioned. A few cons are the size and money factor. Right now digital jewellery is expensive, lacks efficiency and has a few issues related to design aspects. In years to come digital jewellery is going to replace your mobile phones and many other gadgets and lead to humans actually wearing gadgets!
So how does this work? Imagine the components of your phone have been separated from each other and have been incorporated in your jewellery. The basic elements of a phone are the receiver, microphone, display and battery. For instance, earrings act as the receiver for the device and consist of speakers to enable hearing. A necklace consists of a microphone. The user speaks into the microphone to communicate. And the most interesting part is the ring that has a track point which looks like a black pearl. This is used to move the cursor. It also has LEDs that blink to
Click or scan the code to know more
16
THE EEEA REVIEW
And finally we come to the last stage: finishing. Polyjet technique provides highly accurate product with very smooth and fine finishing. Any support material used during the printing can be dissolved when dipped in certain liquids or water depending on the material used. The amount of manual work to be done after the finishing is very less and mostly not required.
Have you ever wondered how a bike in the market was made? Or how a multifunctional robot was made? Each product that is available to you in the market has gone through many stages starting as a project and ending up as a product. It all starts with an idea. Now this idea goes to a design stage from where it is further led to an implementation stage. After the making of an idea the next major step is to make a product prototype. A prototype is the first functioning working model of your product. So how do you make your prototype? Industrial techniques if used for making a prototype can require a lot of money, and things tend to get tough since you’ve just started with your idea. Hence the rapid prototyping technique is used. Rapid prototyping cuts the cost of making your prototype by a large amount and also provides you more speed at which your prototype can be made.
Polyjet technique has several benefits over traditional prototyping techniques and renders better results. The resin cartridges are easy to replace and use. The best part of it is its applications! Apart from the usual uses, it has been used to make a few pills, prosthetics and various organs of the body. The only down side is that resins cost a little more than plastics. Polyjet technique is definitely going to be used very commonly in the future! It will be made available to the average people in a few years to come. Just wanting to make almost anything out of a 3D printer just how cool is that!
There are various rapid prototyping techniques available to people today. The most commonly used techniques are Fused Deposition Modelling(FDM) , Selective Laser Sintering(SLS), Stereolithography(SLA), Polyjet 3D printing etc. Polyjet 3D printing technique has 3 basic stages: modelling, printing and finishing. This technique is very much similar to SLA. The first aspect is modelling. A digital model is first created using a CAD software. Any correction in the design of the model is done before in the modelling stage itself before printing. After the digital model has been made, the process advances to the next step i.e. printing. Now the designed model has to be sliced. Slicing is basically dividing the model into many layers, of thickness that may vary from 16 micro metres to 100 micro metres depending on the product requirements. A G- code is also made during this process. A G code is a numeric code that instructs the machine how to make the product. It tells the machine on which axis it should move, how much it should move to the left or right and how fast it should move. The nozzles of the machine contain resins. The product is printed layer by layer. The resin is squeezed out of the nozzle in liquid form. It is then made to pass through UV light that cures the resin which is in this case solidification. The printing period depends on the complexity of the model as well as the machine used. The way in which this technique differs from SLA is by the material used in the machine. Resins are used in place of plastic and also different materials can be used at the same time while printing.
Click or scan the code to know more
17
THE EEEA REVIEW
WATER PURIFICATION AT NANOSCALE : IISc researchers produce a better water purification membrane Department of Materials Engineering and a team in IISc invented a water purifying system that could even eliminate harmful bacteria at a nanoscale level. The filter consisted of a porous membrane made of two polymers, along with minute quantities of silver, titanium dioxide and carbon nanotubes. The pores filter out the micron-sized bacteria, while the silver-titanium-carbon mixture kills the bacteria. The combination of all the three nanoparticles was superior in killing the pathogenic bacteria E. coli.
A NON-INVASIVE HEART CONDITION DETECTOR: A non-invasive device that can measure heart and lung, called the Fibre Bragg Grating Heart Beat Device, was invented by S Asokan, Professor at Department of Instrumentation and Applied Physics and his team. The device simply needs to be wrapped around a person’s chest, while the sensors detect cardiac activities, measure blood pressure, count blood glucose levels, and monitor respiration. Made of an optical fibre sensor, this device can easily help detect heart conditions early. The unique design offers additional capabilities such as monitoring nascent morphology (detection of original heart beat shape) of cardiac and breathing activity, heart rate variability, heart beat rhythm etc, which can assist in early clinical diagnosis of many conditions associated with heart and lung malfunctioning, said the research team.
Source : http://www.thebetterindia.com/
18
POCKET ECG MONITOR: With India being the heart-disease capital of the world, this innovative, credit-card-sized ECG monitor has the potential to touch millions of hearts. Access to and cost of proper diagnosis and treatment are the biggest hurdles faced by a majority of the population. With the pocket ECG monitor, Sanket people can measure ECG and stress levels by using just a thumb-touch. Produced report can be sent to the patient’s doctor instantly. A smartphone app linked to the device is used to store and share the data. This comes in handy, especially when doctors want to monitor the patient’s heart remotely. Sanket can also raise an alarm when it notices something abnormal. The Sanket team does 100,000 free ECG tests every month for those who cannot afford it. Their ECG monitors will be placed in areas where there is no access to big hospitals, so that those living in remote rural areas or even urban slums can get access to better technology and better cardiac health.
THE EEEA REVIEW
The Enigmatic Rings by Disha Roy Of all the planets,none seem to capture our fascination like the glorious Saturn. The fascination is likely due to the enormous rings that make the Saturn's rings which are also one of the greatest mysteries in space. But as our spacecrafts are getting closer than ever to the rings, we're getting a more complete picture of what they are made up of and how they cause to exist. There are 7 rings in total and, as expected, they are named in the order they were discovered. Because they are named in an ordered system, astronomers have named the rings as letters such as Ring A, Ring B and Ring C all of the way up to Ring G. While you might think that the names of these rings are quite boring, they helped astronomers refer to them quickly and easily - after all, Saturn’s rings are quite complicated! A and B are two brightest rings whereas C and D are barely visible. The ring F is very narrow and held together by two moons- Pandora and Provetheus. Farther out is the ring G and finally the ring which has been the most puzzling to scientists,because unlike the other rings, E is thought to be made up of ice particles sprayed out of volcanic geysers near the south pole of the moon Enceladus. But how were the rings formed and how old they could be? The dawn astronomy in the 20th and 21th centuries revealed the mysteries to many questions. The rings were created when comets or asteroids collided with one or more of the planet's moons,shattering them into pieces. Scientists surmised that the ice in the ring would have been more dirtier if it had been gathering dust for four billion years. Eventually when the Cassini spacecraft sent back the clearest images yet of Saturn's rings the scientists said that the original estimate may have been correct after all. They believe it is likely that the ring particles were recycled to 4 billion years and that will continue to exist long in future. However, it is for sure that the splendid elegance of the majestic rings of Saturn will glister in the dramatic background of the cosmos for ages. The mysteries of the rings are as intertwined as the bends and twists in the rings,themselves.At present these paradoxes might be difficult to solve. But ,who can process? Tomorrow you might find yourself "ring walking".
Source : http://www.kidsastronomy.com/
19
THE EEEA REVIEW
20
THE EEEA REVIEW
Black Holes some of the strangest and most mysterious objects in the Universe. A black hole is the result of the death of a high mass star and is the ultimate end state of the core of that star. Hence this article intends to discuss at length, the formation of a Black Hole. Roughly speaking, stars can be classified into two groups- low mass stars and high mass stars. Stars produce energy in their cores by fusing hydrogen into helium. This process is quite complicated but in the end, four protons plus some other ingredients combine and form one helium nucleus and in the core of a star, this process takes place innumerable number of times, ultimately, leading to the production of a huge amount of energy which is enough to power a star. Now, the rate at which hydrogen fusion occurs depends on how much pressure the star has in its core.
Black holes come in different sizes. Their masses can vary from a minimum of 3 times the mass of the sun to a dozen or more times the mass of the sun. These are called stellar mass black holes. If they take up more mass, say from a star or a gas cloud which comes very close, they will grow bigger in size and their event horizon will grow accordingly. These are called super massive black holes, which may be millions or billions of kilometres across. Black holes may also help determine the fabric of the universe. Matter hurtling towards a black hole produces a lot of frictional heat. Black holes also spin like deep whirlpools in space. The combination of friction and spin results in a significant amount of the matter falling toward a black hole, sometimes more than 90 percent, not passing through the event horizon but rather being flung off, like sparks from a sharpening wheel.
A low mass star has lesser pressure and therefore fusion of hydrogen takes a much longer time. They live for very long periods, as compared to high mass stars and are known as red dwarfs and can shine for a trillion years.
This heated matter is channelled into jet streams that hurtle through space, away from the hole at phenomenal velocities, usually just a tick below the speed of light. The jets can extend for millions of light-years, drilling straight through a galaxy.
If a star has more than eight times the mass of the sun, it can have a temperature in excess of five hundred million degrees Celsius in its core. This makes the carbon in the core to fuse into neon, magnesium and sodium. The core goes on heating and contracting and causes further fusion of all these elements into Silicon at a temperature of 1.5 billion degrees. Then again, when the temperature is about 2 to 3 billion degrees, Silicon fuses to form iron along with some other elements.
The next topic is time; which is way more of a mind bender. Time and black holes have a very strange relationship. In fact, time itself is an unusual concept. It is known that time is relative which means that time does not move at the same speed for everybody. Time, as Einstein discovered, is affected by gravity. If extremely accurate clocks are placed on every floor of a skyscraper, then clocks on the lower floors, closer to the centre of the Earth, where gravity is stronger, will tick a little slower than the ones on the top floors. This is unnoticeable because the variances are a spare billionth of a second here and there. Clocks on global positioning satellites have to be set to tick slightly slower than those on Earth’s surface, otherwise, GPS would not be accurate.
In the meantime, the size of the star becomes massive due to the tremendous amount of energy produced in it and turns into a super giant. Now, the fusion of iron in the core produces a different result. Instead of producing energy, it absorbs energy and also absorbs all the electrons in the core which also helps in supporting the mass of the star. The core further shrinks and heats up and the gravity becomes immensely strong, resulting in the collapse of the star. This happens in a fraction of the speed of light. The size now decreases to merely a couple of dozen kilometres across in just a few thousandths of a second. Its gravity is increased so much that all its mass and matter come crashing at an extremely high speed down to the core, ferociously heating it. As all these matter fall in, a monster shock wave created at the core due to the collapse moves outward and slams into all the material that are moving in. The explosive energy so formed slows down the material falling in. In about a fraction of a second, it can carry about 100 times as much energy as our sun will produce in its entire lifetime. These little neutrinos do not like interference with other matter. The material moving down to the core is so dense that huge waves of neutrinos slam into them and the impact is tremendous. The material stops falling in, reverses its course and blasts outward. The star explodes. This is called a Supernova, one of the most terrifying and destructive events in the Universe. The expanding gas blasts out at 10% the speed of light. The energy released is huge enough to be seen halfway across the Universe. Two kinds of objects are created after a supernova depending on whether the mass of the core was less or more than 2.8 times the mass of the sun. In lower mass stars, the core supports itself by a phenomenon called Electron Degeneracy Pressure, a stellar application of Pauli’s Exclusion Principle. No two electrons can occupy the same space even under the pressure of a collapsing star of several solar masses. But electron degeneracy pressure fails in the case of low mass stars. The protons, electrons and other subatomic particles combine under the huge pressure and form neutrons. However, if the mass of the core is more than 2.8 times the mass of the sun, the pressure increases by such a vast amount that the neutrons can no longer resist the collapse of the star and the core collapses all the way down to a point where not even light can escape from it. When the size of the core drops down to roughly 18 kilometres, escape velocity (the velocity required to overcome the gravitational pull of a planet or star) at its surface becomes equal to the speed of light. Now when the core shrinks smaller than this size, neither matter nor light can escape from it because nothing can travel faster than the speed of light, which makes it an infinitely deep, black hole.
Now, what happens if an object crosses the event horizon with a clock? A person observing from outside will observe that the object is frozen and the clock has stopped ticking. Although, this is not practically possible because the light emitted by the object will have to fight the intense gravity of the black hole to come out, for which it would lose energy. This is very similar to the Doppler Redshift and is known as a Gravitational Redshift. But, when a person just hits the event horizon of a black hole, all of time would pass. All the light coming towards the person from the universe would be blue shifted, becoming such high energy that it would burn up the person. However, recently, Stephen Hawking, the British physicist, proved that black holes leak—the seepage is called Hawking radiation—and given enough time, will evaporate entirely. But that will take trillions upon trillions of years, when black holes may be the only objects remaining in our universe. Sound familiar? We do know, after all, what became of at least one singularity. Our universe began, 13.8 billion years ago, in a tremendous big bang (theory). The moment before, everything was packed into an infinitesimally small, massively dense speck—a singularity. Perhaps the multiverse works something like an oak tree. Once in a while an acorn is dropped, falls into the ideal soil, and abruptly sprouts. Hence with a singularity, the seed of a new universe also sprouts. In a similar way, like a sapling oak, we would never send a thank-you note to our mother. For the message to escape our universe, it would have to move faster than the speed of light. Again, sound familiar? The evidence for what could reside in a black hole is compelling. Look to your left, look to your right. Pinch yourself. A black hole might have originated in another universe. But we may be living in it.
A common misconception about black holes is the idea that they move across the universe and suck in anything that comes into their path. A black hole does have extreme gravitational forces but that force can be felt only when we cross the Event Horizon (the line that divides the inside of the black hole at which the escape velocity is the speed of light and the outside) of the black hole. Suppose our sun turns into a black hole-although, it will not, but for argument sake-its mass would remain the same; however, its diameter would decrease to about 865,000 miles to less than four miles. The earth and the other planets would continue to orbit the black hole with the same pull as they would orbit the sun, on their usual path.
21
THE EEEA REVIEW
Wireless Power Transfer Ali Abbas Magar,II year,EEE by
Wireless Power Transfer holds the promise of freeing us from the tyranny of power cords. This technology is being incorporated into all kinds of devices and systems. Let's take a look!
The Wired Way The majority of today's residences and commercial buildings are powered by alternating current (AC) from the power grid. Electrical stations generate AC electricity that is delivered to homes and businesses via high-voltage transmission lines and step-down transformers. Electricity enters at the breaker box, and then electrical wiring delivers current to the AC equipment and devices that we use every day—lights, kitchen appliances, chargers, and so forth. All components are standardized and in agreement with the electrical code. Any device rated for standard current and voltage will work in any of the millions of outlets throughout the country. While standards differ between countries and continents,within a given electrical system, any appropriately rated device will work.
Wireless Power Technology Wireless Power Transfer (WPT) makes it possible to supply power through an air gap, without the need for current-carrying wires. WPT can provide power from an AC source to compatible batteries or devices without physical connectors or wires. WPT can recharge mobile phones and tablets, drones, cars, even transportation equipment. It may even be possible to wirelessly transmit power gathered by solar-panel arrays in space. WPT has been an exciting development in consumer electronics, replacing wired chargers. The 2017 Consumer Electronics Show will have many devices offering WPT. The concept of transferring power without wires, however, has been around since the late 1890s. Nikola Tesla was able to light electric bulbs wirelessly at his Colorado Springs Lab using electrodynamic induction.
Three light bulbs placed 60 feet (18m) from the power source were lit, and the demonstration was documented. Tesla had big plans and hoped that his Long Island-based Wardenclyffe Tower would transmit electrical energy wirelessly across the Atlantic Ocean. That never happened owing to various difficulties, including funding and timing.
22
THE EEEA REVIEW
WPT uses fields created by charged particles to carry energy between transmitters and receivers over an air gap. The air gap is bridged by converting the energy into a form that can travel through the air. The energy is converted to an oscillating field, transmitted over the air, and then converted into usable electrical current by a receiver. Depending on the power and distance, energy can be effectively transferred via an electric field, a magnetic field, or electromagnetic (EM) waves such as radio waves, microwaves, or even light.
Where WPT Works All WPT technologies are currently under active research, much of it focused on maximizing power transfer efficiency and investigating techniques for magnetic resonant coupling. In addition to the idea of walking into a room equipped for WPT and having your devices charge automatically, much more ambitious projects are in place. Across the globe, electric buses are becoming the norm; London's iconic double-decker buses are planning for wireless charging, as are bus systems in South Korea, Utah, and Germany.
Qi Charging, an Open Standard for Wireless Charging
Using WiTricity, invented by MIT scientists, electric cars can be charged wirelessly, and those cars can wirelessly charge your mobiles! (Using Qi charging, of course!) This wireless technology is convenient, to be sure, but it may also charge cars faster than plug-in charging can.
While some of the companies promising WPT are still working to deliver products, Qi (pronounced "chee") charging is standardized, and devices are currently available. The Wireless Power Consortium (WPC), established in 2008, developed the Qi standard for battery charging. The standard supports both inductive and resonant charging technologies.
WPT works everywhere!
Inductive charging has the energy passing between a transmitter and receiver coil at close range. Inductive systems require the coils to be in close proximity and in alignment with each other; usually the devices are in direct contact with the charging pad. Resonant charging does not require careful alignment, and chargers can detect and charge a device at distances up to 45 mm; thus, resonant chargers can be embedded in furniture or mounted in shelving. When first introduced, Qi charging was low power, about 5W. The first smartphones using Qi charging were introduced in 2011. In 2015,
Conclusion While Tesla's dream of having power delivered wirelessly for everyone's use is still far from feasible, many devices and systems are using some form of wireless power transfer right now. From toothbrushes to mobile phones, from cars to public transportation, there are many applications for wireless power transfer.
Qi was expanded to include 15W, which allows for quicker charging.
Click or scan the code to know more
23
THE EEEA REVIEW
FLYTEFlying bulb by DHEERAJ
24
THE EEEA REVIEW
Click or scan the code to know more
The 'Flyte' levitating light bulb cleverly uses magnets to float in the air and hovers above a wooden base. The hi-tech light bulb can be switched on and off by just touching the base and it draws power wirelessly from the charger block it hovers above. It was invented by art scientist, Simon Morris, 37, who was inspired by the concept of a hover board as a child. This is a levitating light bulb. It hovers using magnets and draws power wirelessly from the charger block it hovers above. 'Flyte levitates using magnetic levitation. A magnet is embedded in the bottom cap of the bulb and suspends in the air through its opposing force from the wooden base. 'Levitation is achieved when the bulb is placed at the centre point of the base. 'Power is transferred wirelessly from the base to the bulb with a technology called induction.' The block of wood needs to be plugged into a wall for the light bulb to turn on and levitate, while the base can also be used as a wireless charging station for smartphones and other devices. If left un-touched, Flyte consumes very little power and will remain levitating and rotating endlessly.'The light bulb has a lifetime of 22 years based on six hours use a day or 11 years at 12 hours per day.' The long lifetime is due to the bulb using low-energy LED lights to create light, rather than filaments as some other more short-lived light bulbs use. The base of the bulb can also be used to charge your Smartphone as well.
25
THE EEEA REVIEW
Decision Review System by Nilesh Ojha System of using DRS in a match
The System The Decision Review System (abbreviated as DRS) is a technology-based system used in the sport of cricket. The system was first introduced in Test cricket, for the sole purpose of reviewing controversial decisions made by the on-field umpires as to whether or not a batsman had been dismissed. The system was first tested in an India v Sri Lanka match in 2008,and was officially launched by the International Cricket Council (ICC) on 24 November 2009 during the first Test match between New Zealand and Pakistan at the University Oval in Dunedin. The ICC initially made the DRS mandatory in all international matches,but later made its use optional, so that the system would only be used if both teams agree. The ICC has agreed to continue to work on the technology and will try to incorporate its use into all ICC events. In September 2013, the International Cricket Council announced that for a trial period starting in October 2013, a team's referrals would be reset to two after 80 overs in an innings in Test matches. Previously each team had a maximum of two unsuccessful reviews in an innings.
Components of DRS There are three components in DRS. The use of Snickometer was suspended but was reintroduced in 2013. Ultra Edge was introduced in 2016, as a better option to Snickometer.
As per the new updated rules, each team may make no more than two unsuccessful review requests per 80 overs during a Test match, and no more than one unsuccessful review request per innings during a One Day International. A fielding team may use the system to dispute a "not out" decision and a batting team may use it to dispute an "out" decision. The fielding team captain or the batsman being dismissed invokes the challenge by signalling a "T" with the arms. Once the challenge is invoked, acknowledged, and agreed, the Third Umpire reviews the play. Additionally, at their discretion, field umpires may request the Third Umpire to review certain close calls such as line calls (to determine run outs and stumpings), boundary calls (to see if a batsman hit a four or a six), or for close catch calls where neither umpire is sure if a catch was made. A challenge is only used in situations that did or could result in a dismissal: for example, to determine if the ball is a legal catch or if a delivery made the criteria for a leg before wicket dismissal. The Third Umpire then reports to the on-field umpire whether his analysis supports the original call, contradicts the call, or is inconclusive. The on-field umpire then makes the final decision: either re-signalling a call that is standing or revoking a call that is being reversed and then making the corrected signal. Each team can initiate referrals up to the limit on unsuccessful reviews. Under the DRS rule, only clearly incorrect decisions are reversed; if the Third Umpire's analysis is within established margins of error or is otherwise inconclusive, the on-field umpire's original call stands.
·The Hawk Eye technology Hawk-Eye, Eagle Eye, or Virtual Eye: ball-tracking technology that plots the trajectory of a bowling delivery that has been interrupted by the batsman, often by the pad, and can determine whether it would have hit ·Ultra-edge, which is termed as Hot Spot's enhanced version of Snickometer. When the ball has hit the batsman's pads, Ultra Edge creates four frames and automatically uses all the frames to give precise result. It is able to differentiate more clearly over sounds created by bat, pads or clothing. ·Hot Spot: Infra-red imaging system that shows where the ball has been in contact with bat or pad. Improved cameras were introduced for the 2012 season. ·Real-time Snickometer, which uses directional microphones to detect small sounds made as the ball hits the bat or pad.
The Hot Spot Technology
26
THE EEEA REVIEW
TAEKWONDO by Anamika Ranjan
Taekwondo is a Korean martial art which specializes in high head kicks, spin kicks, jump and kick techniques. It was developed in 1940-50s and has come a long way since then. The fighters of this martial art are awarded points based on the kicks executed against their opponents.
al that reacts to the impact of the foot and releases a small amount of current which is transmitted. It detects a maximum of 4 impacts in a second. The sending and receiving of the transmitted signal takes 0.01 second. The reading is transmitted to an electronic scoreboard where the scores are determined.
At the 2008 Beijing Olympics, in the final moments of the match, Ms. Stevenson delivered a high head kick while fighting against Cheg Zhong. The judges failed to see this kick and an incorrect decision was made. Later, after reconsideration, the judgement was changed and Stevenson won the bronze medal. Due to these manual errors, the World Taekwondo Federation stepped up and introduced several technological changes in their marking system. Mr. Song, a Silicon Valley engineer, developed a wireless electronic device which is secured in the protective guard of the fighter. This guard consists of an impact sensor that is connected to a magnet, working on Wi Fi, present inside the footgear of the opponent. As this magnet approaches the sensor, it detects and records the force of the opponent's foot on the body. The impact sensor has 2 parts which takes two different reading and the average is calculated.
Another change seen during the years is the use of an octagonal mat instead of a square one. This is because extra points are to be awarded for the kicks where they turn their backs as a way to encourage more spin and kick techniques rather than just defending themselves. Smart tracking devices are used to train the fighters. The devices are used for tracking the motion of the fighter, and testing fitness by monitoring the heart rate.
Sources-economist .com, Washington, martial
In the Rio Olympics, a headgear was introduced which measures the impact of the kick to the head. The sensor used is piezoelectric, a crystalline materi-
27
THE EEEA REVIEW
Travel destination of this season by Soham Mandal Manali Situated at an elevation of over 6,000 feet is a beautiful hill station nestled in the mountains of Himachal Pradesh. This magical snow-covered place is frequented by tourists in winters. Manali offers numerous breathtaking places to visit and a lot of activities that one can indulge in.
Where to stay? There are numerous hotels and beautiful cottages built in the heart of the mountains. So, staying there won’t be an issue.
What you can expect in winter?
History and Culture of Manali
● ·Adventure Sports such as paragliding, skiing,
Manali is named after the Hindu lawgiver Manu. Manali exactly means “the abode of Manu”. Legend has it that sage Manu stepped off his ark in Manali to recreate human life after a great flood had deluged the world.
etc. ● ·The green valleys which are covered with snow are mesmerizing to watch.
Rakshas, the nomadic hunter tribe and shepherds from Kangra Valley are believed to be the earliest inhabitants of Manali. One of the most popular inhabitants of the city was the ‘nar’. Manali was part of the erstwhile princely state of Mandi which merged with India in 1948.
● ·Snow would be all around you and not to forget you might also end up with
experiencing
a
snowfall.
Lord Raghunathji, a form of Lord Ram, was believed to be the ruler of Manali and the erstwhile princely rulers ruled the kingdom in trust for Raghunathji. How Raghunathji came to be ruler of Manali has an interesting legend associated with it.
● ·A visit to the Hadimba Temple, Tibetan
Raja Jagat Singh, who ruled the valley in 17th century, contracted leprosy after he was cursed by a peasant. However, modern Manali history began with the advent of the British. The British developed the land as a sanctuary from the oppressive heat of the plains during summer. They planted apple and released trouts in the rivers of Manali.
● One can sit peacefully near the river Beas– for
Monastery – for people who like to keep travelling.
those who travel to places for
taking
some rest. ●·The temperature drops to -10 degree Celsius, so you can actually feel the
presence
of
winter.
How to go? Travelling to Manali is the easiest from Delhi. Volvo buses ply between Delhi and Manali both in the morning and evening. The distance is around 540 kms by road. These buses take around 11 hours to complete this journey.
28
THE EEEA REVIEW
Tips Do make this trip in January – February at least once in your life, you wouldn’t regret it.
29
THE EEEA REVIEW
“After you ma’am.” said an old man of 60 and held the door open for me and welcomed me with a big smile ,and that very phrase made me realize , nope I wasn’t in India any more where people would probably run into someone to get the first place for literally everything! . . I was in a place where people would help you without any kind of expectation. Where people would love to compliment you to their heart’s fullest, where strangers would smile at you and Cops could be friends with you! Yes, I was in the United States of America, which made this year’s summers to be my one of the best memories I have ever had or maybe I will ever have. Going to America, more than to any other part of the world is really special, and weird because you already know a lot about the American culture before setting your foot in there. Thanks to movies, TV shows, and the global broad casting features. We arrived at the Atlanta Airport, Georgia, my sister’s place and my adventures began. which topped with some evergreen famous places like Georgia aquarium, Washington DC, New York covering some states like, Philadelphia,Virginia,Pennsylvania,Tennessee Kentucky and many more. Then we started off with our American Road trip. As I write this I can recall the whole beauty of the roads. The never ending valleys, the country side blue sky, and the lonesome heritage houses, and most importantly the extremely quiet traffic and the roads cleaner-thanthe-bedrooms which didn’t even have a sign of dirt! We reached our defined destinations after every 8 hours drive. Washington’s mesmerizing Capitol House, The ferocious Niagara Falls and The Big Apple City New-York. All of them were amazingly beautiful! New-York. It’s really a huge City. With only a few hours in our hand it was a tough decision regarding which place to visit and which one to leave. finally we decided to go for -THE EMPIRE STATE BUILDING and TIME SQUARE.
standing on the 86th floor of the EMPIRE STATE BUILDING, 1050 feet high. Bracing the winds which felt like cold December air I walked up to the the observatory deck for a 360 degree view of the city.It was the most spectacular sunset I’ve ever seen. As the sun melted below the horizon, the sky was streaked with a display of beautifully burnt oranges and reds. And as darkness fell, the lights of New York’s skyscrapers and buildings flickered on! TIME SQUARE. Even at 2’o’ clock in the night it all felt so colorful! The Lights, the Streets, The Shops ,The Musical theaters, it was all so lively and cheerful. And one can actually see there, people roaming around dressed up as Superman, Batman, Spiderman, Minions, Woody, to make the kids happy. ! To be honest it felt like I was watching a movie. Or was a part of the movie called ‘The-Amazing Spiderman’ imagining myself jumping and running around the skyscrapers and buildings of timesquare!! I wanted to make the most of every single minute spent in America. I wanted to see everything America could show me, if only I had some more time to stay there. But apart from these luxuries the thing which really touched my heart was the people of America. Unlike others they are very independent. They dare to dream big. And they never give up till the time they change there CANT’S into CANS and DREAMS into Plans. So I would like to tell you guys if given a chance never miss to visit the US, the story of my first time visit to America is a lot longer than what could be squeezed in here into a couple of paragraphs .and once you visit there you would know it is a lot more fun than one could ever imagine.
by Biswadeepa Bhattacharya
30
THE EEEA REVIEW
Why did CyanogenMod die? What is LineageOS? All the important details by Prateek Gulati The Cyanogen company did not shut down, nor did the operating system CyanogenMod – it’ll just change names. CyanogenMod OS will rebrand as LineageOS and will be separate from Cyanogen Inc., the company, which will operate separately from the open source OS. It is recommended to stay away from LineageOS until it’s well underway in its new brand shell. A company making this big of a switch, and making such a switch due to a failure in its structure should be treated with all due caution in their time of transition. There’s something to be said for staying loyal to a group of developers that’ve done good work – but right this minute, we must use caution. According to a blog post on December 23rd, 2016 on CYNGN dot com, the official CyanogenMod OS project ends at the end of this year. “As part of the ongoing consolidation of Cyanogen, all services and Cyanogen-supported nightly builds will be discontinued no later than 12/31/16. The open source project and source code will remain available for anyone who wants to build CyanogenMod personally.” According to Lineage OS – the new webpage for the open source project, “Yes, this is us.” They refer to the open source development community, the “community of developers, designers, device maintainers, and translators” contributing to the CyanogenMod project. This project Lineage OS begins as a fork of CyanogenMod and includes both a fork of the CM source code and pending patches.
Those with CyanogenMod installed on phones or tablets right now should consider installing a more basic version of Android now, as no new support for the operating system will be offered.
“The CyanogenMod Team” posting to CyanogenMod.org (before it was taken down this week) suggested the following. “This fork will return to the grassroots community effort that used to define CM while maintaining the professional quality and reliability you have come to expect more recently.” A LineageOS community page suggests that support will be able to be found through IRC or their new Reddit. Both Contribution channels – Gerrit and the Wiki for the OS – are not yet operational. They’ll be around sooner than later – and Github action can be found at /lineageos. This is still a Wild West stage for Lineage OS, and we’ll be interested to see where it goes from here. For everyone seeking out archives of CyanogenMod data – good luck to you! We’ll see you on the other side – UPDATE: With this Lineage OS (Lineage Central) Twitter portal.
31
THE EEEA REVIEW
ELECTRICAL ENGINEER and the THINGS THAT WE CAN FIX ON OUR by ANUBHAV PANDEY
Weak/Dead battery
Clutch : Not engaging properly
The battery that is safely secured onto your bike is indeed the lifeline of its entire electrical system. For two wheelers equipped with just an electric start, the starter motor is wholly dependent on the battery. Only if the battery carries sufficient charge would it be able to crank up the motor that demands a fairly high voltage from the battery.
When you are starting your bike and the transmission is in gear, you need to pull the clutch lever properly. Sometimes, the clutch does not engage correctly and creates a starting problem. In such condition, bring your transmission in neutral and try again.
Blocking intake or exhaust
On a relatively weak battery one would not be able to use the electric start. Some signs of a dead or a weak battery are when you push the horn button or switch on the headlights, none actually work well or report total failure.
Blocked air box or muffler exit is also a condition that creates starting problem, which can occur due to any reason including pranksters in your neighbourhood. So, you should also check the intake and exhaust system of your bike if there is anything extra in them.
No fuel When your fuel level goes down, it is very difficult to judge its availability using the gauge and that could also be a reason why your bike isn't starting. At that time, you can use some old school techniques to check if your bike has fuel or not.
Loose spark plug wire Loose spark plug wire is not a new thing for motorcycle riders; it can occur due to the jerks or could be a prank. You don't need any mechanic to fix this problem. Just unplug and re-plug the connectors and try to start the motorcycle again.
One of the easiest way is to shake your bike gently when on main stand and wait to hear that typical telltale slosh of remaining fuel, if any, from the tank. Alternatively you could also check it using the flashlight of your mobile phone.
Engine cut off switch It is one of the most common things we forget to check before getting annoyed with the starting problem. Most of the time we use the ignition key to turn off the motorcycle instead of the engine kill or cut off switch. So when we use it, we forget to turn off the switch sometimes and keep trying to crank the engine.
Clogged fuel tank vent There is a very small vent provided on the fuel tank of your motorcycle for the outlet to supply fuel continuously to the intake system. In most of the bikes in India, it is the keyhole of the fuel tank cap. When this vent gets clogged, the tank stops the supply of fuel to the lower system. You can unclog the vent with a very thin wire or pin along with a forced blow in that hole.
32
THE EEEA REVIEW
Imaging Solar Cells in 3D By Pratyush Tripathi
Scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to use optical microscopy to map thin-film solar cells in 3-D as they absorb photons. The new technique images optoelectronic dynamics in materials at the micron scale, or much thinner than the diameter of a human hair. This is small enough to see individual grain boundaries, substrate interfaces, and other internal obstacles that can trap excited electrons and prevent them from reaching an electrode, which saps a solar cell’s efficiency. So far, scientists have used the technique to better understand why adding a specific chemical to solar cells made of cadmium telluride (CdTe)—the most common thin-film material—improves the solar cells’ performance. “To make big gains in photovoltaic efficiency, we need to see what’s happening throughout a working photovoltaic material at the micron scale, both on the surface and below, and our new approach allows us to do that,” says Edward Barnard, scientific engineering associate at the Molecular Foundry. He led the effort with James Schuck, the director of the Imaging and Manipulation of Nanostructures facility at the Molecular Foundry. The imaging method is born out of a collaboration between Molecular Foundry scientists and Foundry users from PLANT PV Inc., an Alameda, California-based company. While fabricating new solar cell materials at the Molecular Foundry, the team found that standard optical techniques couldn’t image the inner-workings of the materials, so they developed the new technique to obtain this view. Next, scientists from the National Renewable Energy Laboratory came to the Molecular Foundry and used the new method to study CdTe solar cells. To develop the approach, the scientists modified a technique called two-photon microscopy (which is used by biologists to see inside thick samples such as living tissue) so that it can be applied to bulk semiconductor materials. The method uses a highly focused laser beam of infrared photons that penetrate inside the photovoltaic material. When two low-energy photons converge at the same pinpoint, there’s enough energy to excite electrons. These electrons can be tracked to see how long they last in their excited state, with long-lifetime electrons appearing as bright spots in microscopy images. In a solar cell, long-lifetime electrons are more likely to reach an electrode. In addition, the laser beam can be systematically repositioned throughout a test-sized solar cell, creating a 3-D map of a solar cell’s entire optoelectronic dynamics. The method has already shed light on the benefits of treating CdTe solar cells with cadmium chloride, which is often added during the fabrication process. Scientists know cadmium chloride improves the efficiency of CdTe solar cells, but its effect on excited electrons at the micron scale is not well understood. Studies have shown that the chlorine ions tend to pile up at grain boundaries, but how this changes the lifetime of excited electrons is unclear. The new imaging technique could help scientists make more informed decisions about improving a host of thin-film solar cell materials in addition to CdTe, such as perovskite and organic compounds.
Click or scan the code to know more
Source : http://www.azom.com/
33
THE EEEA REVIEW
The very word “theory” conjures up images of geometry class or, worse, physics lab. Scary stuff. Scarier, when you put the word “music” in front. “Music theory?” Music is supposed to be fun, carefree, an audio expression of our feelings. Music is not science. Is it? Well, not rocket science, anyway (though the ancient Greeks did study harmony as part of the school of mathematics). We can nit-pick ourselves to death with this question – after all music is sound and sound is physics (again? arrrrgggg!). But let’s save ourselves from trouble and anxiety by approaching music theory, and especially how it relates to the aspiring guitarists, with a simple idea: music theory is actually simple and fun. Okay, it’s not really simple, but it’s nowhere near as complicated as you might think. And it really is a lot of fun. Let’s begin. So let us first understand the very meaning of a Scale. Oftenconfused weather it is a group of 7notes (Sa Re Ga Ma Pa Dha Ni) or 8 (Sa Re Ga Ma Pa Dha Ni Sa). Let us concede that it is a set of 8 notes. No don’t think that the Indian form Sa Re Ga Ma… is of no use for guitarist in you, it’s just the Major Scale you have been humming, which concludes that there are two scales one is major of course and other is minor. Though, understanding Major Scale is what you need. So what are these then? A A# B C C# D D# E F F# G G# This might be confusing but no it isn’t. These are just different sounds which have been distinguished under certain formulas you just never need to know. Trust me never. Just know that these exist and are called Notes There are certain notations that might confuse you now and then if you don’t know them, just simple rules: ·
If any notation has (denoted as flat) in it, it just means to get one step back (in reference to above, coz yeah... its half step). Which means Bb is nothing but A#, and same for others.
·
#, this symbol is called sharp (easy?).
Now that, it’s clear what a scale is, let us see how we can just put it in a simple table.
I C
C#
II D
D#
III E
IV F
F#
V G
G#
VI A
A#
VII B
VIII C
This is the simple major scale of C, see it starts with C and ends with C (don’t get confused with see and C there, hmm).
34
THE EEEA REVIEW
Keep in mind the “I” note is called the “root” or “tonic.” This is to ensure that we are all starting with the same “Sa” when constructing our scales. Using this same chart and “rotating” either the notes or the Roman numerals in one direction or another, we can figure out any major scale in any key. Let’s pick up any key, say F#. In realigning the notes, F#is now the root (“I”) of the scale. So that is where we start. First we put out all the notes (in half steps) and then place the Roman numerals in their proper place (whole step, whole step, half step, whole step, whole step, whole step, half step). This is what you should have:
I F#
II G#
G
A
III A#
IV B
V C#
C
D
VI D#
E
VII F
VIII F#
And finally, let’s remove the notes that do not have Roman numerals above them and there it is! – a scale in F sharp major.
I F# Sa
II G# Re
III A# Ga
IV B Ma
V C# Pa
VI D# Dha
VII F Ni
VIII F# Sa
Isn’t it so simple? So, this was an overview of the simple and not so physics concept of music. Read the next issue of the magazine when Chord Theory will be explained, trust me it’s simpler.
35
THE EEEA REVIEW
Siddharth Jp, II year, EEE
EEEA CREATIVES A month ago the readers were asked to send their art and drawing submissions to the association email. Out of the many entries, best 6 images were chosen by the creatives domain. (Other submissions will be uploaded on the facebook page as well as the instagram page of the EEE Association)
Siddharth Jp, II year, EEE
36
THE EEEA REVIEW
Sneha Bhattacharya, II year, EEE
Shatarupa Chakraborti, III year EEE
Shalini Haldar, III year EEE
37
THE EEEA REVIEW
Abhinandan Tiwari, III year EEE
Bhartendra Singh Chauhan, III year EEE
38
THE EEEA REVIEW
Highlights of the Month by Prateek Gulati Facebook Messenger allows video chat with up to 50 people Facebook Messenger has launched Group Video Chat on desktops and both the Android and iOS platforms, allowing up to 50 people to join a video chat at one time. A video icon in the upper right corner of the screen activates the feature. While up to six people can be seen at once, other friends can join chat via voice.
Google Confirms It Will Launch Two Android Wear Smartwatches In Early 2017 Technology giant Google has confirmed that it will launch two flagship smartwatches in the first quarter of 2017. The smartwatches will not have Google or Pixel branding, but will be branded by the company that is manufacturing it. Both the smartwatches will be powered by Android Wear 2.0 and will be the first devices to launch with the new platform.
Physicists observe light spectrum of antimatter for 1st time European physicists have reported the first ever optical spectrum measurement of antimatter, revealing it to be the exact mirror image of ordinary matter. Antimatter is composed of particles with same mass as matter, but with opposite charges. The experiment, that compared antihydrogen with hydrogen, is consistent with the theory which states the two should have identical spectroscopic properties.
World's first solar road opens in France The world's first solar road made with 30,000 square feet of solar panels has been opened in the French village of Normandy. The one-kilometre long road took five years and cost $5.2 million to develop. It will be used for a two-year test period to check if it can generate enough energy to power street lighting in the village
39
THE EEEA REVIEW
Here are the Association Core members. They will be in charge of the student body of the Electrical and Electronics department PRESIDENT
: DR. K. VIJAYKUMAR
CO-ORDINATORS
: Ms T.M. THAMIZH THENDRAL Ms S. USHA Ms A. GEETHA
VICE PRESIDENT
: KOLLA SRIKANTH PRANAV BHARADWAJ (Technical) ALLADA SAI ROHIT (Sports) INDRANEEL PATHA (Finance)
TECHNICAL
SECRETARY
: D BHARADWAJ
PR AND MEDIA`
: AMIT KUMAR
: PRATEEK GULATI ABHISHEK IYER
M V SAI PRAVEEN
DHRUV GUPTA CULTURAL
DIVYANSH SAWANT
: SHIKAR SAHAI ANAMITRA BORA
SPORTS
MONISHA DAS FINANCE
: DV NIKHIL
VISHAL DUBEY EMCEE
K NITHIN RAJ SETTY
: B KALAIVANI SHALINI HALDAR
PHOTOGRAPHY
SPONSORSHIP
DEEPAK REDDY
: PARTH SHARMA D NIRUPA ANGELIN
PUBLICITY
: ANIRUDH REDDY G SAI KAUSHAL
: NILESH PRANAY V NAVEEN SRI SAI
DOCUMENTATION : I SAI VARUN SANCHARI BANERJEE
: RAJAN CHANDAK V ARCHANA IYER
DISCIPLINE CREATIVE
: SOUPTIK CHAKRABARTI
: M MAYANK PATHAK SOUMYADIP
DESIGN
: PIYUSH PRATIK KALLOL CHATTERJEE
https://www.facebook.com/eeeassociation.srm/