Molecular Electronics:A new technology competitive to semiconductor technology

Semiconductor integration beyond Ultra Large Scale Integration (ULSI), through conventional electronic technology facing some problems with fundamental physical limitations. Beyond ULSI, a new technology may become competitive to semiconductor technology. This new technology is known is as Molecular Electronics.

Molecular based electronics can overcome the fundamental physical and economic issues limiting Si technology. Here, molecules will be used in place of semiconductor, creating electronic circuit small that their size will be measured in atoms. By using molecular scale technology, we can realize molecular AND gates, OR gates, XOR gates etc.

The dramatic reduction in size, and the sheer enormity of numbers in manufacture, are the principle benefits promised by the field of molecular electronics

Tele-Immersion (TI) :Free full Engineering seminar reort

It is 2010 and you have a very important meeting with your business associates in Chennai. However you have visitors from Japan coming for a mega business deal the same day. Is there any technology by which you can deal with both of them? The answer is yes and the name of that technology is Tele-Immersion. Tele-Immersion is a technology by which you’ll interact instantly with your friend on the other side of the globe through a simulated holographic environment. This technology, which will come along with Internet2, will change the way we work, study and get medical help. It will change the way we live. Tele-Immersion (TI) is defined as the integration of audio and video conferencing, via image-based modeling, with collaborative virtual reality (CVR) in the context of data-mining & significant computation. The 3D effect behind the tele-immersion makes it feel like the real thing. The ultimate goal of TI is not merely to reproduce a real face-to-face meeting in every detail, but to provide the “next generation” interface for collaborators, world-wide, to work together in a virtual environment that is seamlessly enhanced by computation and large databases. When participants are tele-immersed, they are able to see and interact with each other and objects in a shared virtual environment.

Tele-immersion can be of immense use in medical industry and it also finds its application in the field of education

Cylinder Deactivation: A fast emerging technology to save fuel

With alternatives to the petrol engine being announced ever so often you could be forgiven for thinking that the old favorite the petrol engine is on its last legs but nothing could be further from the truth and possibilities for developing the petrol engines are endless. One of the most crucial jobs on the agenda is to find ways of reducing fuel consumption, cutting emissions of the green house gas CO2 and also the toxic emissions which threaten air quality. One such fast emerging technology is cylinder deactivation where a number of cylinders are shut down when less is needed to save fuel.
The simple fact is that when you only need small amounts of power such as crawling around town what you really need is a smaller engine. To put it another way an engine performs most efficiently when its working harder so ask it to do the work of an engine half its size and efficiency suffers. Pumping or throttling losses are mostly to blame. Cylinder deactivation is one of the technologies that improve fuel economy, the objective of which is to reduce engine pumping losses under certain vehicle operating conditions.

When a petrol engine is working with the throttle wide open pumping losses are minimal. But at part throttle the engine wastes energy trying to breathe through a restricted airway and the bigger engine, the bigger the problem. Deactivating half the cylinders at part load is much like temporarily fitting a smaller engine.
During World War II, enterprising car owners disconnected a spark plug wire or two in hopes of stretching their precious gasoline ration. Unfortunately, it didn’t improve gas mileage. Nevertheless, Cadillac resurrected the concept out of desperation during the second energy crisis. The “modulated displacement 6.0L V-8- 6-4” introduced in 1981 disabled two, then four cylinders during part-throttle operation to improve the gas mileage of every model in Cadillac’s lineup. A digital dash display reported not only range, average mpg, and instantaneous mpg, but also how many cylinders were operating. Customers enjoyed the mileage boost but not the
side effects. Many of them ordered dealers to cure their Cadillacs of the shakes and stumbles even if that meant disconnecting the modulated-displacement system


Like wide ties, short skirts and $2-per-gallon gas, snoozing cylinders are back. General Motors, the first to show renewed interest in the idea, calls it Displacement on Demand (DoD). DaimlerChrysler, the first manufacturer to hit the U.S. market with a modern cylinder shut-down system calls its approach Multi- Displacement System (MDS). And Honda, who beat everyone to the punch by equipping Japanese-market Inspire models with cylinder deactivation last year, calls the approach Variable Cylinder Management (VCM)
The motivation is the same as before — improved gas mileage. Disabling cylinders finally makes sense because of the strides achieved in electronic power train controls. According to GM, computing power has been increased 50-fold in the past two decades and the memory available for control algorithms is 100 times greater. This time around, manufacturers expect to disable unnecessary cylinders so seamlessly that the driver never knows what’s happening under the hood.

MANUFACTURING THROUGH ELECTRO CHEMICAL MACHINING

ABSTRACT:
The machining of complex shaped designs was difficult earlier, but with the advent of the new machining processes incorporating in it chemical, electrical & mechanical processes manufacturing has redefined itself. This paper intends to deal with one of the revolutionary process called Electro Chemical Machining (ECM).

INTRODUCTION:
Electro chemical machining (ECM) is the controlled removal of metal by anodic dissolution in an electrolytic medium in which the work piece is the anode & the tool is the cathode.
Working: Two electrodes are placed at a distance of about 0.5mm & immersed in an electrolyte, which is a solution of sodium chloride. When an electrical potential of about 20V is applied between the electrodes, the ions existing in the electrodes migrate toward the electrodes.
Positively charged ions are attracted towards the cathode & negatively charged towards the anode. This initiates the flow of current in the electrolyte. The electrolysis process that takes place at the cathode liberates hydroxyl ions & free hydrogen. The hydroxyl ion combines with the metal ions of anode to form insoluble metal hydroxides &the material is thus removed from the anode. This process continues and the tool reproduces its shape in the work piece (anode). The high current densities promote rapid generation of metal hydroxides and gas bubble in the small spacing between the electrodes. These become a barrier to the electrolyzing current after a few seconds. To maintain a continuous high density current, these products have to be removed continuously. This is achieved by circulating the electrolyte at high velocity through the gap between the electrodes. It is also to be noted that the machining gap size increases. Therefore to maintain a constant gap the cathode should be advanced towards the anode at the same rate at which the material is removed.

CHEMICAL ROCKET ENGINES

Chemical rocket engines, like those on the space shuttle, work by burning two gases to create heat, which causes the gases to expand and exit the engine through a nozzle. In so doing they create the thrust that lifts the shuttle into orbit. Smaller chemical engines are used to change orbits or to keep satellites in a particular orbit. For getting to very distant parts of the solar system chemical engines have the drawback in that it takes an enormous amount of fuel to deliver the payload. Consider the Saturn V rocket that put men on the moon: 5,000,000 pounds of its total take off weight of 6,000,000 pounds was fuel. The problem is that all the energy for chemical engines comes from the energy stored in the propellants.
Electric rocket engines use batteries, solar power, or some other energy source to accelerate and expel charged particles. These rocket engines have extremely high specific impulses, so they are very efficient, but they produce low thrusts. The thrusts that they produce are sufficient only to accelerate small objects, changing the object’s speed by a small amount in the vacuum of space. However, given enough time, these low thrusts can gradually accelerate objects to high speeds. This makes electric propulsion suitable only for travel in space. Because electric rockets are so efficient and produce small thrusts, however, they use very little fuel. Some electric rockets can provide thrust for years, making them ideal for deep-space missions. Satellites or other spacecraft that use electric rockets for propulsion must be first boosted into space by more powerful chemical rockets or launched from a spacecraft.

CARBON NANOTUBES

Carbon Nanotubes -- tiny tubes about 10,000 times thinner than a human hair -- consist of rolled up sheets of carbon hexagons.
HISTORY
Discovered in 1991 by researchers at NEC, they have the potential for use as minuscule wires or in ultrasmall electronic devices.
To build those devices, scientists must be able to manipulate the Nanotubes in a controlled way.
DEVELOPMENT

IBM researchers using an atomic force microscope (AFM), an instrument whose tip can apply accurately measured forces to atoms and molecules, have recently devised a means of changing a nanotube's position, shape and orientation, as well as cutting it.

Continuously variable transmission (CVT):A potential solution to this fuel economy dilemma

After more than a century of research and development, the internal combustion (IC) engine is nearing both perfection and obsolescence: engineers continue to explore the outer limits of IC efficiency and performance, but advancements in fuel economy and emissions have effectively stalled. While many IC vehicles meet Low Emissions Vehicle standards, these will give way to new, stricter government regulations in the very near future. With limited room for improvement, automobile manufacturers have begun full-scale development of alternative power vehicles. Still, manufacturers are loath to scrap a century of development and billions or possibly even trillions of dollars in IC infrastructure, especially for technologies with no history of commercial success. Thus, the ideal interim solution is to further optimize the overall efficiency of IC vehicles.
One potential solution to this fuel economy dilemma is the continuously variable transmission (CVT), an old idea that has only recently become a bastion of hope to automakers. CVTs could potentially allow IC vehicles to meet the first wave of new fuel regulations while development of hybrid electric and fuel cell vehicles continues. Rather than selecting one of four or five gears, a CVT constantly changes its gear ratio to optimize engine efficiency with a perfectly smooth torque-speed curve. This improves both gas mileage and acceleration compared to traditional transmissions.
The fundamental theory behind CVTs has undeniable potential, but lax fuel regulations and booming sales in recent years have given manufacturers a sense of complacency: if consumers are buying millions of cars with conventional transmissions, why spend billions to develop and manufacture CVTs?
Although CVTs have been used in automobiles for decades, limited torque capabilities and questionable reliability have inhibited their growth. Today, however, ongoing CVT research has led to ever-more robust transmissions, and thus ever-more-diverse automotive applications. As CVT development continues, manufacturing costs will be further reduced and performance will continue to increase, which will in turn increase the demand for further development. This cycle of improvement will ultimately give CVTs a solid foundation in the world’s automotive infrastructure.