Archive for June 2011

Automobile Fuel Economy



Shikha Jodhani 
Third Year
Civil






With more attention than ever being focused on energy conservation, vehicle fuel efficiency, and new alternatives such as hybrid cars and bio-based fuels, the significance of road construction materials on energy usage is often overlooked.
The fact is, that concrete pavements give vehicles greater fuel
efficiency, and saves energy. As a result, fuel costs and CO2
emissions are reduced.
Another factor is energy needed for construction. Because concrete pavements are produced with locally sourced and abundant raw materials, less fuel is required to transport the raw
materials and produce concrete. Asphalt pavements include petroleum, which is most-often
imported from various regions around the world.
Driving vehicles on concrete roadways provide better fuel mileage because there’s not as much deflection or ‘rolling resistance’ as with asphalt pavements.
A deflected pavement absorbs energy that otherwise would be used to propel the vehicle forward.



Research Facts:
In the project ‘Pradhan Mantri Gram Sadak Yojna’ the   pavement  was   evaluated   by   Falling  weight Deflectometer using a dynamic load of 45kN on 300mm diameter plate. The equivalent elastic modulus of the 100mm compacted flexible concrete was about 4500 MPa, three times the modulus of high strength bituminous concrete used in major highways. Its expected life is 15 to 20 years. The cost of 250m long pavement with a hard shoulder
of laterite boulder was found to be Rs.4.00 lakhs and the cost
per kilometer is estimated as Rs16.00 lakhs .



Just one glance at Mumbai’s landmark Marine Drive will amply demonstrate the durability and resilience of concrete roads. Even after seven decades of its construction, this seafront arterial road shows few signs of distress as compared to much newer stretches built in recent years.
REDUCING U.S. DEPENDENCE ON FUEL




CONSTRUCTING CONCRETE PAVEMENTS:

Concrete roads have a life cycle of 50 years and also help save 15% in fuel consumption. A combination of fly-ash based concrete roads is environment-friendly and has a 50% longer life cycle.
Concrete roads are typically built in a continuous, single-layer method called slipform paving. The result is a very efficient operation requiring a comparatively low amount of fossil fuel for construction vehicles. Asphalt pavements require a large amount of energy to heat materials up to 325°F at the production plant and are placed in multiple layers (often 3 or more for highways).
For a 10" thick pavement, an asphalt roadway would require about 5½ times more diesel fuel to construct than a concrete road.
> It takes 2.90 gallons of diesel fuel per ton of asphalt road.
> It takes just 0.50 gallons of diesel fuel per ton of concrete road.

Tips to save fuel..

ü While going on a long drive try to keep the windows close since open windows increases resistance to wind flow that increases fuel consumption by as much as 20%. This logically means that if one spends Rs200 a week on petrol, he can save Rs40 a week, which sum up to Rs160 a month. This may seem silly to some who feel they don’t require to do saving but one must know that same money piles up to big amount in long terms and will pay off during their rainy days.

ü More and more car drivers have changed their priorities and now want all to save fuel. Start-stop systems have therefore become standard features in modern automobiles. When the vehicle comes to a standstill, the engine is automatically shut down and started up again when the driver depresses the clutch before moving off. It’s an approach that certainly saves fuel, but the technology does its drawbacks. As the starter motor draws off considerable current from the system, the on-board voltage level can fall from its normal level of 12 volts to as low as 6 volts. Which means the radio and ventilation will switch off, and the lights will dim.To prevent such complications during starting, a DC/DC converter was the solution. It aims to boost up the voltage to a stable 12 volts. Its design is very compact and can be easily integrated into the vehicle. This is one of the innovations between battery and energy management.A start-stop system significantly increases the number of times the engine is started, it is essential to protect the starter battery against overload. Therefore, another innovation comes to place which is called the intelligent battery sensor which provides an additional check. The sensor monitors battery status and transmits the information to the cars body controller, which only enables the start-stop functions if the three key battery parameters; capacity, performance and age are in the required range.
DC/DC converter and IBS therefore make the ideal combination for saving fuel. The converter adds comfort and convenience, while the intelligent battery sensor protects the battery and ensures that the vehicle has no problem starting.




ü Make sure your tires are properly inflated .This prevents increased rolling resistance. Under-inflated tires can cause fuel consumption to increase by as much as 6%. Check tire pressure at least once a month, when the tires are 'cold' (i.e. when the vehicle has not been driven for at least three hours or for more than 2km). Start by checking tire pressures in your driveway. Note any tire that is underinflated, and then drive to the nearest gas station to add air. Check tire pressures again at the station, and inflate the low tires to the same level as the others (these will likely have higher pressure than they did in the driveway, since the tires have heated up.) 


Radial tires can be under inflated yet still look normal. Always use your own tire gauge for consistent results. On average, tires lose about 1 psi per month and 1 psi for every 10 degree drop in temperature.


To determine the correct tire inflation for your car, consult the car's operator manual or ask your tire dealer. Do not inflate your tires to the 'maximum allowed' pressure which is marked on the side of your tires.


According to the Energy Information Administration, tire efficiency could save approximately 800,000 barrels of oil a day


ü Tighten your gas cap  - If you don't tighten up the gas cap to the second click, gas can evaporate. According to the Car Care Council (carcare.org), loose, missing or damaged gas caps cause 147 million gallons of gas to evaporate every year. Think "aerodynamic" and "lightweight". Reduce drag. Out on the open highway, keep windows rolled up to reduce drag. Remove bicycle and ski racks when not in use. Excess weight also uses more fuel. Remove unnecessary items from inside the vehicle, trunk or truck bed. An extra 100lbs (48 kg) of weight can increase your fuel bill by 2%. 




ü The 30-second Warm Up

§  Do not let your engine idle for more than 30 seconds after its initial start. Engines warm up faster when they are in motion.
§  Idling for more than 30 seconds not only wastes fuel but also harms your engine, since the amount of lubricating oil being pumped to the engine’s various parts is the minimum when the engine is in neutral and idling.
§  Depress the accelerator just once when needed, as unnecessary pumping wastes fuel.





           

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Technology behind 3D television


Akash Bohare & Rishika Gaud 
Second Year
Chemical
                                                              
How 3D works..

The first of the 3d movies made its debut in 1922 using the oldest form of technology - anaglyph images - to produce stereoscopy. To understand this we need to consider how the eyes work to see in real life. Assuming no vision issues, our eyes are spaced a number of centimeters apart, so when looking at any object the eye send information to brain from two slightly different perpectives. The brain interprets this information and combines the two images to create depth perception and see one 3 dimensional image.

Stereoscopy originally involved taking a single image, and adding two additional image layers with slightly different perspectives. One layer was tinted red and the other blue. When watching a 3D movie, the audience would wear cardboard 3D glasses that had one red and one blue lens. Each lens would filter out its similarly colored image layer, thereby tricking the brain into creating a 3D image by mashing the two images together. 




Stereoscopy








Stereoscopy is most widely accepted method for capturing and delivering 3D video. It involves capturing stereo pairs in a two-view setup, with cameras mounted side by side, separated by the same distance as between a person's pupils. 

If we imagine projecting an object point in a scene along the line-of-sight (for each eye, in turn) to a flat background screen, we may describe the location of this point mathematically using simple algebra. In rectangular coordinates with the screen lying in the Y-Z plane (the Z axis upward and the Y axis to the right) and the viewer centered along the X axis, we find that the screen coordinates are simply the sum of two terms, one accounting for perspective and the other for binocular shift. Perspective modifies the Z and Y coordinates of the object point by a factor of D/(D-x), while binocular shift contributes an additional term (to the Y coordinate only) of s*x/(2*(D-x)), where D is the distance from the selected system origin to the viewer (right between the eyes), s is the eye separation (about 7 centimeters), and x is the true x coordinate of the object point. The binocular shift is positive for the left-eye-view and negative for the right-eye-view. 

For very distant object points, it is obvious that the eyes will be looking along the same line of sight. For very near objects, the eyes may become excessively "cross-eyed". However, for scenes in the greater portion of the field of view, a realistic image is readily achieved by superposition of the left and right images (using the polarization method or synchronized shutter-lens method) provided the viewer isn't too near the screen and the left and right images are correctly positioned on the screen. Digital technology has largely eliminated inaccurate superposition that was a common problem during the era of traditional stereoscopic films.

Technologies..

There was another problem with these colorful anaglyph images, though. They altered the coloring of the movies and interpreting the different images would often cause headaches after a short time. This led to the creation of the polarized 3d glasses we see in cinemas today.but the 3d technology used in movies is different than what is used in homes.

To overcome the above problem, the newest glasses innovation is a LCD shutter glasses which work on a system known as 'active technology'. These active shutter glasses work by alternately blocking the vision in each eye in conjunction with the refresh rate of the display screen. 3D TVs that use this form will display alternate images with slightly differing perspectives at a high rate, and the glasses darken each lens in time with the alternating images, causing the brain to do the classic image mash-up.


This technology works in a similar fashion as the older glasses, by blocking what image enters which eye. Shutter glasses simply take the idea to the next logical step by literally blacking out the lenses at a high rate of speed. Subsequently, shutter glasses are able to offer a much clearer three-dimensional picture than older methods





















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SSL: Secure Sockets Layer

Anurag Kumar 
Second Year
CSE
                                                              
SSL (Secure Sockets Layer) is the standard security technology for establishing an encrypted link between a web server and a browser. This link ensures that all data passed between the web server and browsers remain private and integral. SSL is an industry standard and is used by millions of websites in the protection of their online transactions with their customers. The protocol uses a third party, a Certificate Authority (CA), to identify one end or both end of the transactions.
To be able to create an SSL connection a web server requires an SSL Certificate. When you choose to activate SSL on your web server you will be prompted to complete a number of questions about the identity of your website and your company. Your web server then creates two cryptographic keys - a Private Key and a Public Key.
The Public Key does not need to be secret and is placed into a Certificate Signing Request (CSR) - a data file also containing your details. You should then submit the CSR. During the SSL Certificate application process, the Certification Authority will validate your details and issue an SSL Certificate containing your details and allowing you to use SSL. Your web server will match your issued SSL Certificate to your Private Key. Your web server will then be able to establish an encrypted link between the website and your customer's web browser.
The complexities of the SSL protocol remain invisible to your customers. Instead their browsers provide them with a key indicator to let them know they are currently protected by an SSL encrypted session - the lock icon in the lower right-hand corner, clicking on the lock icon displays your SSL Certificate and the details about it. All SSL Certificates are issued to either companies or legally accountable individuals.

The following is a screen shot of a web page implementing the protocol using VeriSign.


The VeriSign logo can be seen on the right side bottom of the page. Also https is mentioned instead of http in the address bar. Clicking on the VeriSign Trusted icon displays information about the web site such as:

VeriSign logo

Another screen shot showing the result of clicking on the VeriSign logo.

Another protocol for transmitting data securely over the World Wide Web is Secure HTTP (SHTTP). By convention, URLs that require an SSL connection start with https instead of http Whereas SSL creates a secure connection between a client and a server, over which any amount of data can be sent securely, S-HTTP is designed to transmit individual messages securely. Typically an SSL Certificate will contain the domain name, the company name, the address. It will also contain the expiration date of the Certificate and details of the Certification Authority responsible for the issuance of the Certificate. When a browser connects to a secure site it will retrieve the site's SSL Certificate and check that it has not expired, it has been issued by a Certification Authority the browser trusts, and that it is being used by the website for which it has been issued. If it fails on any one of these checks the browser will display a warning to the end user letting them know that the site is not secured by SSL.  


What Happens When a Web Browser Connects to a Secure Web Site?
      This is in short how it works.
ü     A browser requests a secure page (usually https ://).
ü     The web server sends its public key with its certificate.
ü     The browser checks that the certificate was issued by a trusted party (usually a trusted root CA), that the certificate is still valid and that the certificate is related to the site contacted.
ü     The browser then uses the public key, to encrypt a random symmetric encryption key and sends it to the server with the encrypted URL required as well as other encrypted http data.
ü     The web server decrypts the symmetric encryption key using its private key and uses the symmetric key to decrypt the URL and http data.
ü     The web server sends back the requested html document and http data encrypted with the symmetric key.
ü     The browser decrypts the http data and html document using the symmetric key and displays the information.

                                            
Why Encryption?
Encryption Protects Data during Transmission. Web servers and Web browsers rely on the Secure Sockets Layer (SSL) protocol to create a uniquely encrypted channel for private communications over the public Internet. Each SSL Certificate consists of a public key and a private key. The public key is used to encrypt information and the private key is used to decipher it. When a Web browser points to a secured domain, a level of encryption is established based on the type of SSL Certificate as well as the client Web browser, operating system and host server’s capabilities. That is why SSL Certificates feature a range of encryption levels such as "up to 256-bit". Strong encryption, at 128 bits, can calculate 288 times as many combinations as 40-bit encryption. That's over a trillion times a trillion times stronger. At current computing speeds, a hacker with the time, tools, and motivation to attack using brute force would require a trillion years to break into a session protected by an SGC-enabled certificate.

A basic example:
“Hi, how are you?”  Can be encrypted as “?uyo ear who ,Hi”. Techniques can vary according to sensitivity of the information being transmitted.


So, in short SSL Encryption safe guards you and your information online. Thus it protects you from any frauds.


SSL, Trust and E-Commerce
When customers buy online, they trust that the company will protect their personal information and use it only as intended. Premium SSL Certificates and daily Web site malware scanning together help assure the customers that the site is safe from search to browse to buy.
ü     Concerns Keep Shoppers from Buying Online
Despite steady growth in e-commerce, concerns about fraud and identity theft continue to keep potential customers away. In the past two years, 62% of shoppers have become more concerned about their online security.
48%  have become more concerned about giving personal information online due to  fear of cybercriminals

36% are less likely to enter credit/debit card or bank account related information online because of concern that it will be intercepted and stolen.

Even though online retailers secure online transactions with encryption, 73% of consumers want more assurance that their information is secure. (Javelin Strategy and Research, March 2009)

ü     Shopping Cart Abandonment Reduced and Online Sales on the Rise
When Web site visitors see the SSL encryption enabled seal, they are less likely to abandon a transaction and more likely to do business with online. Case studies show a 10-36% increase in online transactions when such a logo/seal is displayed. In a recent study, 11% of respondents decided not to conduct business with the site because they did not see thesame.
  

Defensive Measures 
For the sake of convenience, many users will continue to use unsecured networks at cafes, libraries, airports and other public places for Internet access. Web site operators should safeguard their users’ data privacy regardless of the types of network users employ. By taking protective measures before a side jacking attack succeeds, companies can avoid losing customers and incurring crippling costs from litigation and redressing negative publicity. Organizations can help defend against side jacking attacks by enabling SSL protection throughout the entire user session for their customers, not just at login.

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