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Showing posts from December, 2014

Mini generators make energy from random ambient vibrations...........!!

By:Prayag Nao

Tiny generators developed at the University of Michigan could produce enough electricity from random, ambient vibrations to power a wristwatch, pacemaker or wireless sensor.

The energy-harvesting devices, created at U-M's Engineering Research Center for Wireless Integrated Microsystems, are highly efficient at providing renewable electrical power from arbitrary, non-periodic vibrations. This type of vibration is a byproduct of traffic driving on bridges, machinery operating in factories and humans moving their limbs, for example.
The Parametric Frequency Increased Generators (PFIGs) were created by Khalil Najafi, chair of electrical and computer engineering, and Tzeno Galchev, a doctoral student in the same department.
Most similar devices have more limited abilities because they rely on regular, predictable energy sources, said Najafi, who is the Schlumberger Professor of Engineering and also a professor in the Department of Biomedical Engine…

Hydrogen-Powered Personal Helicopter............!!!

By:Prayag Nao

A personal helicopter weighing just 230 lb created sizzling news when it flew on hydrogen with zero emission. With an ability to carry payloads up to 800 lbs, this pocket Hercules can fly for 90 minutes. Fitted with easy controls, this reaches a speed of 100 knots thanks to a pair of small yet powerful motors mounted on it. Two common and easily available things – Hydrogen peroxide (H2O2) and a catalyst – combined to bring about a milestone in personal aviation history with attention to the environmental issues as well! Avimech has combined these two to power engine in to an innovative machine.

unique combination:
Avimech has combined two ideas – a rocket and a helicopter – to create this cute little personal aviation machine baptizing it as ‘Dragonfly.’ Actually this idea to utilize H2O2 and a catalyst has been around for some time. But to use them to power this hybrid version of a rocket in a helicopter is the brain child of Avimech.
Motors at rotor tips:

Flat Tower: Innovative Architectural Solution

By:Prayag Nao

High-rise buildings and skyscrapers have been the most favored architectural solutions for highly populated cities. It is a commendable idea for combining height – growing more vertically – and for its small footprint without hogging precious soil which is at a premium in most cities. But sporadic eruptions of skyscrapers do not add to the beauty of the skyline of any city nor does it add any way to the locale topographical charm. The solution seems to be structures that solve housing problem for the populace without spoiling the beauty of the city.

 2011 eVolo Skyscraper Competition
The 2011 eVolo Skyscraper Competition is an annual event for architectural designs. In 2011 year’s goal was to find an architectural solution for housing in thickly populated urban areas without disturbing the existent city skylines as well as not hogging precious green spaces. This flat tower designed by Yoann Mescam, Paul-Eric Schirr-Bonnans, and Xavier Schirr-Bonnans from Fra…

Artificial Electronic Super Skin – Powered By Stretchable Solar Cells

By:Prayag Nao

Zhenan Bao, Stanford researcher, is keen to create “Super skin.” Taking her previously created super-sensitive sensor a step ahead, she is now creating a super skin that will be self-powered with renewable clean solar energy. Bao and her team have designed polymer solar cells that are flexible and can be stretched to power the ’super skin’.

Previous sensor
Ms Bao had successfully built a sensor flexible and very sensitive to any pressure. It was able to detect even touch-down pressure of a fly. She had made this over a foundation of a flexible organic transistor made of supple polymers and materials which are carbon based. Touch-sensing is achieved by the fluctuations in the current flow which is caused by an elastic rubber layer shaped like myriad inverted pyramids.

Rationale for sensing
Changing the transistor’s semiconducting material according to the type of material kept on sensor, the sensor can sense whether it is touching a chemical or a biological mate…

Fuel Cell Basics........!!!!

By:Prayag Nao
What is a fuel cell?A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes.  Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodes.
Hydrogen is the basic fuel, but fuel cells also require oxygen. One great appeal of fuel cells is that they generate electricity with very little pollution–much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
One detail of terminology: a single fuel cell generates a tiny amount of direct current (DC) electricity. In practice, many fuel cells are usually assembled into a stack. Cell or stack, the principles are the same. 
How do fuel cells …

How Vacuum Cleaners Work ?

By:Prayag nao

When you sip soda through a straw, you are utilizing the simplest of all suction mechanisms. Sucking the soda up causes a pressure drop between the bottom of the straw and the top of the straw. With greater fluid pressure at the bottom than the top, the soda is pushed up to your mouth. ­
This is the same basic mechanism at work in a vacuum cleaner, though the execution is a bit more complicated. In this article, we'll look inside a vacuum cleaner to find out how it puts suction to work when cleaning up the dust and debris in your house. As we'll see, the standard vacuum cleaner design is exceedingly simple, but it relies on a host of physical principles to clean effectively.

It may look like a complicated machine, but the conventional vacuum cleaner is actually made up of only six essential components:
An intake port, which may include a variety of cleaning accessoriesAn exhaust portAn electric motorA fanA porous bagA housing that contains all the other …

How do seat belts works ?

When the brakes are applied sharply or when the car is impacting something, the vehicle may be stopped, but due to inertia, the passengers motion will keep moving forward. Seat belts can help restrain that motion. Inside, the retractor has a silver-colored bead that is slightly larger than a ball bearing. The movement of the ball due to the vehicle deceleration that is occurring (either brake application or vehicle impact), results in an actuator moving up to lock the spool rotation, locking of the seat belts.

Mechanism for locking the seat belt
1. The silver-colored bead (ball sensor) moves forward
2. The ball sensor pushes the braking claw (actuator) upward
3. To lock the belt, the actuator engages with the lock gear, thus keeping any additional webbing from further extraction.
Extend and Retract In a typical seatbelt system, the belt webbing is connected to a retractor mechanism. The central element in the retractor is a spool, which is attached to one end of the webbing.…

How a Drafting Pencil Works....?

By:Prayag Nao

The modern automatic drafting pencil belongs to a sub set of the group of pencils called mechanical pencils. Mechanical pencils come in all shapes, sizes, colors and lead sizes. They also come in two major types: the twist or screw type, where the lead is advanced by turning some portion of the pencil’s body; and the ratchet type where the lead is advanced in stepped increments by the pressing of a button, either on top of the pencil or on the side or is some special cases, shaking the pencil up and down. The Modern automatic drafting pencil falls into the second category.

Construction  In a typical drafting pencil there will be a lead reservoir tube attached to a brass 3-jawed chuck, which is surrounded by a brass collar called a chuck ring. Generally there is a narrowing in the pencils interior between the chuck ring and the lead reservoir tube trapping them inside the pencil. Above the narrowing, surrounding the lead reservoir tube is a coil spring. …

Ever Wondered What’s Inside This Bead At End Of Your Laptop Charger? Mystery Solved...!

By:Prayag Nao

We all have a basic idea about the purpose of each wire going in and out of our computer. But a few wires seem a bit off when it comes to their appearance. They have a cylindrical bead dangling near the end. So what’s this bead doing on that wire and what purpose does it serve? Today, we are going to unravel this mystery for you.

You will not only find this bead at end of charging cables but also mouse, keyboard and other peripheral cables. It turns out that lump’s called a ferrite bead or, more generically, a choke. It’s a fancy name for what’s basically an electromagnetic wave-bouncer. If you open this bead, you will not find any complex circuits but only a ferrite cylinder that is magnetic in nature. It is this magnetic quality of the bead that serves the purpose.

So basically, when current passes through any cable, it generates electromagnetic interference (EMI). Your electronic gadgets also produce EMI during operation. For example, if you connect a c…

How Guided Missiles Work ?

By:Prayag Nao

In this Post I’m going to write about missile guidance systems . This will be a high level look to give an appreciation of the concepts and techniques used.
NOTE: If you work in the defence industry, please don’t email to remind me it is a little bit more complicated than I have explained it here! Before we start, it's worth taking a step back to find out a little more about this subject.

What is a missile? The first question to answer is what a missile is, and what distinguishes it from a rocket, bomb or other projectile weapon? The simple answer is that a missile has a guidance system to allow it to steer and change course towards its intended target, and also a propulsion system that self drives it.

NASA successfully tests engine that uses no fuel, violates the laws of physics....!

By:Prayag Nao

Very quietly, NASA has tested a space drive that does not use propellant and according to the laws of physics should not work, according to a Thursday story in Wired.UK. The problem is that the drive, called the “Cannae Drive” by its inventor Guiddo Fetta, did work in the NASA directed test. If the efficacy of the drive is confirmed, the implications for space travel are profound. It seems that another technology from Star Trek may be about to become reality,.

The Cannae Drive is apparently based on the work of a British scientist named Roger Shawyer called the EMDrive. It is said to work by bouncing microwaves in an enclosed chamber and thus creating thrust. Despite having built a number of demonstration models, Shawyer has not been able to get anyone interested in his device. Critics reject his relativity explanation for how it works and point out that it violates the conservation of motion.

However it appears that the Chinese quietly tested their own versi…

Fear artificial stupidity, not artificial intelligence..?

By:Prayag Nao

Stephen Hawking thinks computers may surpass human intelligence and take over the world. We won't ever be silicon slaves, insists an AI expert

It is not often that you are obliged to proclaim a much-loved genius wrong, but in his alarming prediction on artificial intelligence and the future of humankind, I believe Stephen Hawking has erred. To be precise, and in keeping with physics – in an echo of Schrödinger's cat – he is simultaneously wrong and right. Asked how far engineers had come towards creating artificial intelligence, Hawking replied: "Once humans develop artificial intelligence it would take off on its own and redesign itself at an ever increasing rate. Humans, who are limited by slow biological evolution, couldn't compete, and would be superseded." In my view, he is wrong because there are strong grounds for believing that computers will never replicate all human cognitive faculties. He is right because even such emasculated …