MECHANICAL BASE

Manufacturing and the different phases of life

2015-05-15T06:56:00.002-07:00

The thing about product process in the world and the and the age of people. This is just a comparison what i think of the worlds manufacturing ability . When i see the stuff in my house mostly, the electronic goods , I think of the manufacturing ability of the Chinese people. And then compare the phases of the human life. I can see the tenure in the mans life of age 30-40 in which he toiling hard to earn his bread being too monotonous in his job of earning his bread.

When I login to the Facebook and whats-app I see the young innovative age of people in there 20 to 30 being active about there ideas. taking on challenges and trying to make them successful.

Thinking of the age of 60 to 80 when the senses are falling apart I see the Japanese. Like the old they have achieved lot in there life they seen all the Ups and downs and gained all the experience in the life. Even they try level hard to make the country build it again again from the natural calamities they know the old age will take them one day but the experience keeps them calm and motivates them to lead through.

The Teen age 15 to 20 and you keep on fighting with yourself there is more kind of breakage them to make. the parents money is available you can spend as your wish . Like wise crude seems to be the boon to the middle east and should and they also spend it guns and weapons to hur each other. Always hostile as the teenagers.

And the most calm or some what satisfied years of life are from 40 to 50. you are accustomed to the job and work before you and the things you have done with your life either you are completed doing it or you are now you cant much about it.

and finally the the rest of the world south Americans, Indians, and Africans since we are born till we only keep on learning from the world.finally this does not mean what age the world it is a baby of mother earth and will keep learning from each other.

Next thing about Energy Production and its Byproducts

2015-05-13T05:10:00.000-07:00

Hello
My thoughts regarding the use of fuel, used by mankind over a period of time. Right from staring with the Neanderthal man understands to burn fire wood for his warmth to the use of 21st century fuels like Hydrogen cell, and Uranium.
The sale of fuels has been a major source of income from small vendors selling wood stock to the oil exporting countries. the whole of energy landscape is ever changing. We have been burning firewood since long and till the last century we hardly knew the impact and the consequences of burning by products. this meant that we knew how useful this is on Small scale and completely lack the vision of the large scale utilization of the produce fuel.
This can be easily seen from the resource utilization of the fuels like crude initially without know to the harmful effects crude as fuel will cause serious constraints like harm to the environment.
this seems to be happening with the current trends suing the battery. We are slowly moving to energy storage options like battery and solar power generation, with the recent launch of the Power wall unit from the Tesla for home users to generate there own energy from the sun. Its good thing to see we reduce the carbon footprint . But this would also mean generation of the tons of waste that will be produce due to the batteries and the wasted solar panels. to be continued.........

Android 4.3 upgrades for Galxy s4

2013-11-23T22:22:00.001-08:00

Just know updated my galaxy s4 with the the android update 4.3.
The functionality of the internet browser has improved a lot.
I was thinking that the 650 mb heavy update would take my mobile to the next level '' kitkat'.
Hope galaxy s4 is updated with new operating system soon...
Just feels exciting if new things could improcve it further...

The RAM usage fir the phone has also been decreased which means now my phone could last half an hour more...

Will be updating what more good has happen to my phone...

New functionality for reading mode seems to added what's fun in that remaind a qurey...

Plastic Product marking in injection molding.

2013-07-09T19:03:00.000-07:00

Items to be marked

Plastic parts should be marked. It is desirable that marking should also be made of the grade and materials,

parts if possible. However, if marking is impossible despite changes of marking locations and sizes,

marking does not have to be performed.

However, marking should be as visible as possible.

(a) When the marking size or location would cause loss of function
(b) When there is not enough space
(c) When it would be difficult due to the way of manufacturing such as the opening and closing direction of
the plastic molding die

(d) When it would not be suitable for the product design

Marking location
Following 1) - 5) below, marking should be performed on as visible locations as possible when disassembling
products manually and separating materials. Visible locations are for example a front face of a product and a convexed
area of the uneven surface. Marking should not be performed on invisible locations.
1) To be shown in locations not hidden by stickers, etc.
2) Priority should be given to the right rather than the left side for plastic parts.
3) Priority should be given to the back rather than the front for plastic parts.
4) Priority should be given to the bottom rather than the top for plastic parts.
5) For container - shaped plastic products, symbols should be placed on the outside, whenever possible.

Possible ways for mold itching the most cost effective way:
http://www.wikihow.com/Acid-Etch-Steel
this also can be used for auto motive plastic products.

The method has its advantages for.

No mold transfer from changes to be made
No high cost machining required.
Marking Locations
Following 1) - 5) below, marking should be performed on as visible locations as possible when disassembling
products manually and separating materials. Visible locations are for example a front face of a product and a con vexed
area of the uneven surface. Marking should not be performed on invisible locations.
1) To be shown in locations not hidden by stickers, etc.
2) Priority should be given to the right rather than the left side for plastic parts.
3) Priority should be given to the back rather than the front for plastic parts.
4) Priority should be given to the bottom rather than the top for plastic parts.
5) For container - shaped plastic products, symbols should be placed on the outside, whenever possible

MODERN TRENDS IN I.C. ENGINES THE BALL PISTON ENGINE

2012-09-15T21:50:00.000-07:00

MODERN TRENDS IN I.C. ENGINES

THE BALL PISTON ENGINE

ABSTRACT

A new power machine concept has been designed and analyzed for production, and proof of principle subscale tests have been performed, with positive results. The machine design concept is applicable as a compressor, pump, motor, or engine. Simplicity of design based on spherical ball pistons enables a low moving part count, high power to weight ratio, elimination of valve train and water cooling systems, and perfect dynamic balance.

The new design concept utilizes novel kinematic design to completely eliminate inertial loads that would contribute to sliding friction. Also, low leakage is maintained without piston rings by using a small clearance on the ball piston, resulting in choked flow past the ball. These features provide the potential for an engine with higher efficiency than conventional piston engines. The engine design utilizes existing recent technology to advantage, such as silicon nitride ball pistons, so a large development effort is not required.
The machine having only a small number of moving parts, the design implements a modified version of the tried and proven thermodynamic Otto cycle when used as an engine. Although the small part count is an important advantage, other advantages exist that will give future engineers new-found freedom in tailoring the combustion process. One great advantage is that the stroke magnitude and rate can be different for different strokes in the cycle (i.e., intake, compression, power, and exhaust). This provides the possibility of converting more energy to shaft power by greater expansion during the power stroke compared to the compression stroke.
Another advantage is the ability to complete any even number of strokes per revolution in a single rotor. This effectively multiplies the power output proportionally if the stroke is maintained constant. Current concentration is on 2 and 4 stroke designs, but 8 or 12 or more stroke rotors are feasible, only limited by centrifugal loads at high speeds for a given rotor size. In addition, rotors can be stacked axially to increase power.
Recently, an engineering breakthrough has enabled the virtual elimination of inertial forces that contribute to friction in the ball piston machine. Friction losses are thus low and independent of operating speed, in contrast to conventional piston engines, where friction losses increase with speed. In addition, recent simulated compressor testing has shown that remaining friction can be nearly completely eliminated by hydrodynamic action of lubricant at the ball piston.

INTRODUCTION

Efforts to develop rotary internal combustion engines have been undertaken in the past, and are continuing. One main advantage to be gained with a rotary engine is reduction of inertial loads and better dynamic balance. The Wankel rotary engine has been the most successful example to date, but sealing problems contributed to its decline. The Hanes rotary engine uses an eccentric circular rotor in a circular chamber with sliding radial vanes. This engine has never been fully tested and commercialized, and has a sealing problem similar to that of the Wankel. A more recent development, the Rand Cam engine , uses axial vanes that slide against cam surfaces to vary chamber volume. Currently under development, it remains to be seen whether the Rand Cam can overcome the sealing problems that are again similar to those of the Wankel.

In the compressor and pump arena, reduction of reciprocating mass in positive displacement machines has always been an objective, and has been achieved most effectively by lobe, gear, sliding vane, liquid ring, and screw compressors and pumps but at the cost of hardware complexity or higher losses. Lobe, gear, and screw machines have relatively complex rotating element shapes and friction losses. Sliding vane machines have sealing and friction issues. Liquid ring compressors have fluid turbulence losses. The new design concept of the Ball Piston Engine uses a different approach that has many advantages, including low part count and simplicity of design, very low friction, low heat loss, high power to weight ratio, perfect dynamic balance, and cycle thermodynamic tailoring capability. These aspects will be discussed in more detail below.

THE DESIGN CONCEPT

Although the design is applicable as a compressor, pump, motor, or engine, the engine implementation will be used for concept discussion. Figure 1and Figure 2 show end and side cross section views, respectively, of a four stroke engine design.

Mode of operation - The basis of the design is ball pistons rolling on an eccentric track. The balls exert tangential force on the cylinder walls which turn the rotor. Useful power is available at the rotor output shaft. The combustion chambers are within the spinning rotor. Chamber porting for intake, compression, power, and exhaust strokes is achieved by passage of the chamber tops across an internal stator with appropriate feeds as the rotor spins.
Beginning at top dead center (TDC) at 0 degrees rotation, the stator intake passage is open to the cylinder and a fuel/air charge is pulled into the cylinder as the ball piston moves radially outward for the first 90 degrees of rotation

Then the intake passage is closed off, and the ball reverses radial direction for the next 90 degrees of rotation, during which time the new charge is compressed (compression stroke).
Just past 180 degrees rotation, the compressed charge is ignited as the cylinder port passes a small ignitor port. Combustion ensues, and the high combustion pressure pushes radially outward on the ball piston for the next 90 degrees of rotation. The ball in turn pushes tangentially on the cylinder wall because of the "slope" of the eccentric ball track, which is now allowing the ball to move radially outward. The tangential force produces useful torque on the rotor (power stroke).
At 270 degrees of rotation, the spent combustion charge is allowed to escape through the exhaust passage as the cylinder port is uncovered. Exhaust is expelled as the ball moves radially inward for the next 90 degrees of rotation (exhaust stroke). Then the cycle repeats.
Important Design Features - The basic operation of the new design is conventional for an internal combustion engine, i.e. a piston reciprocates within a cylinder, and with porting, implements the four strokes of the Otto cycle. However, there are a number of features that make this engine design favorable for high efficiency and emissions control.
The porting required for four stroke operation is achieved with no additional moving parts, and no valve train losses. The porting mechanism is achieved with simple port clocking within the rotor/internal stator bearing interface. Thus, part count is low and the hardware is simple in geometry, with only the rotor and ball pistons as moving parts.
Note that cylinder induction and mixing are aided by centrifugal and coriolis accelerations, because the cylinders are within the spinning rotor.
Sliding friction sites are minimized by the use of a rolling ball piston. Friction at conventional piston rings, piston pin, and connecting rod/crankshaft bearing are eliminated. Sliding friction still exists at the ball/cylinder wall contact, but is minimized by special material selection and working gas hydrodynamics (and possibly local lubrication). The rotor/stator bearing is of a gas or fluid hydrostatic type, so friction is very low at that site.
The use of an eccentric ball track allows tailoring of the chamber volume vs. time to optimize the cycle from a thermodynamic and chemical kinetics standpoint. The only requirement is that the ball return to the starting radius at TDC before intake. For example, the expansion/exhaust stroke length can be made different than for intake/compression for more exhaust energy recovery, or the combustion can be held at constant volume for a certain period.
Multi-cycle rotors can be implemented. Instead of 4 strokes, 8, 12 or more strokes can be traversed in a single revolution. Compressors and pumps can use any multiple of 2 strokes (intake and compression only), either in parallel or staged arrangement. Provided that inertial forces are controlled (to be discussed later), power to weight ratio can therefore be made high. Other engine configuration options are also under investigation, including a dual rotor/intercooler configuration, diesel cycles, and 2 stroke cycles. The dual rotor option is attractive because it allows the compression and expansion ratios to be widely different (on separate rotors), but there are interstage pumping and intercooling losses that must be considered.
The use of many ball pistons, which each undergo the four strokes in clocked fashion, results in smooth power delivery and small net oscillatory forces. In fact, the total ball inertia forces are automatically balanced by symmetry if the number of balls is even. Further, combustion forces can be balanced by using an eight stroke rotor or stacking rotors axially with relative clocking. Also note that a four (or higher) stroke rotor compressor would be balanced.
Novel design of the ball track has been devised that will eliminate inertial forces on each ball that contribute to friction. As the ball moves in and out radially on the eccentric track while the rotor spins, coriolis and other acceleration forces are generated on the ball radially and tangentially. Net tangential inertial forces contribute to friction at the ball/cylinder wall contact point. By changing the ball
rolling radius using a widening/narrowing dual contact track in a prescribed manner, Figure 3, the net tangential inertial forces on the ball can be eliminated. In essence, the track design results in a balance of translational and rotational ball kinetic energy to eliminate tangential force. In other words, the ball track is designed so that the ball rolls around the track in synchronization with the rotor at constant rotation rate. Due to the form of the laws of motion, it is possible to maintain this condition at all rotation rates with a fixed track design. This allows the machine to be run at any high rpm desired, until the mechanical limits of the ball piston rolling on the track are reached (Hertzian stress fatigue). Engine power theoretically increases linearly with rpm. In actuality, intake flow dynamics may limit peak power at very high rpm, but that depends on the intake passageway details.
There is another interesting by-product of the rolling ball approach. The ball spins at very high rates around its own axis, while it is radially compressed by centrifugal forces of rotation about the rotor axis. These two sources of inertial load tend to cancel out in terms of generating internal ball stresses. This allows high engine speeds to be sustained with less ball fatigue damage.
Heat loss is kept low because the engine intake can be configured to flow through the outer stator/rotor cavity. Rotor heat loss is gained by the intake charge, with less loss to the outer stator.

Technical Challenges - The main concerns for operation of the new machine are being addressed in focused subscale testing.
First, leakage through the ball piston/cylinder gap is a significant factor for engine or compressor efficiency, especially at low speeds. Calculations show that the flow is choked during combustion due to high pressure differential and small clearance area. Choking is helpful in keeping leakage to acceptable levels. Engine efficiency predictions based on simple choked flow leakage models are very favorable. Leakage tests performed in subscale testing have shown that leakage is less than the simple models predict, and dependence on ball spin, pressure, and rpm have been and are being characterized.
Second, the friction and wear at the ball piston/cylinder wall sliding interface is important. Engine performance depends on the magnitude of the effective friction coefficient, and high relative sliding speed can contribute to wear. Engine efficiency predictions based on an average friction coefficient of 0.1 or less are very favorable. Subscale tests have proven that the coefficient of friction for a

silicon nitride ball piston on polished steel with no lubrication is about 0.075 +/- 0.03, about the same as estimated.
The wear issue must be proven out mainly by testing with a full range of operating conditions. Thus far, tendency for cylinder wall plasticity has indicated that cylinder material must be of high hot strength and hardness. Large reductions in "wear-in" plastic flow were achieved by changing cylinder walls from 1018 hot rolled steel to 17-4PH hardened to about R_c 44. A material with better hot hardness, such as achievable with M2 high speed tool steel, has been subsequently selected to resist high sliding flash temperatures and completely eliminate cylinder wall plastic deformation. Low cost production options include case hardening, plating over a hot hard substrate, coatings, and other surface treatment technologies.
It is intended to design the machine for no lubrication, except that available from the working gas or fluid. This is most feasible for compressor and pump applications. However, lack of lubrication is a driving consideration in cylinder wall material selection for the engine, based on subscale testing to date with air only. Extra lubrication is a secondary design option that may be best for some applications, especially the engine, where loads are higher. Lubrication can reduce friction coefficient and wear potential and provide hydrodynamic separation at the ball piston/cylinder wall, and also can reduce leakage flow past the ball piston. However, there will be a trade off for residue build up, emissions, and maintenance.

MATERIAL SELECTION

A series of tests to characterize friction and wear of various materials in a simulated ball piston engine/compressor were performed to aid in selection of production materials. Another goal of the tests was to explore the possibility that

this machine could run without lubrication. If unlubricated operation was not possible, tests with instrumentation would be used to confirm the lubricated operation of the machine and the resulting internal loads. Two types of tests were performed. Simple drag sled static coefficient of friction tests were completed to evaluate sleeve materials and coatings. The materials with the lowest friction coefficient then became the focus of operational dynamic tests using a subscale tester.

TEST SETUP

The test setup was designed to simulate the conditions of a typical ball piston compressor. The key response parameters of interest for these tests were friction, wear, and leakage.

The test setup consisted of a test cylinder suspended on load cells, an electric motor driving an eccentric circular steel drive wheel with a simple ball track on the edge, a ball piston driven by the eccentric wheel, compressed air supplied to the cylinder, and a cylinder heater. The test cylinder had a removable sleeve so various material and coating combinations could be tested. The heater was used to change the sleeve temperature to partially simulate compressor thermal conditions and to adjust the ball piston clearance. A drip lubrication system for applying oil to the drive wheel track was fabricated to perform lubricated tests. This system deposited approximately five drops of 10 weight motor oil on to the drive wheel track per minute. A photograph of the test set up is shown in Figure 1.
The configuration of the eccentric drive wheel and its position relative to the cylinder axis results in simultaneous vertical oscillation and spinning of the ball within the cylinder and oscillating mechanical leverage angle that closely approximates the actual operation of a ball piston machine. Of greatest importance, given a cylinder internal pressure via supply air, ball/cylinder wall interaction forces (including sliding friction) are closely simulated.
Dynamic and static cylinder support loads, cylinder and tank pressure, and cylinder temperature were measured via a PC-based data acquisition system. The operating friction coefficient between ball piston and sleeve was indicated by correlation with one of the load cell signals. Leakage was calculated using tank pressure drop measurements over time. Wear was visually observed on the ball and sleeve after testing.

TESTING

First, static friction tests were performed on uncoated steel, cadmium plated steel, steel coated with Alumide, steel coated with Chromide, and steel coated with TiN, TiCN, TiAlN, or TiAlCN ion deposition treatments. In addition, tests were done after polishing TiAlN and TiAlCN samples with fine grit lapping compound. The polished TiAlCN coating was selected as the best sleeve coating for sub scale testing. It exhibited the lowest friction coefficient against a silicon nitride ball, about 0.06, comparable with that of smooth plain steel. This was a welcomed result, showing that the hard ceramic-like coating did not adversely interact with the silicon nitride ceramic. Polishing was necessary to remove sputter residue that increased roughness. The tests indicated that using a highly polished surface would minimize friction coefficient in production.

Next, operational tests were performed with a wide variety of sleeves and several ball types. Mild steel, Chrome plated steel, plain M2 tool steel, and TiAlCN coated M2 tool steel sleeves were tested. Silicon nitride, Alumina, chromium steel, Teflon, and Nylon balls were used. In addition, cryogenically treated plain M2 and TiAlCN coated M2 tool steel sleeves were tried. This cryo treatment was purported to improve wear resistance.

RESULTS

First, the Teflon and Nylon balls were eliminated from consideration due to insufficient dimensional stability. They deformed enough just in storage to preclude fitting the cylinder.

Although some of the remaining materials and coatings worked better than others, none of the unlubricated tests were successful. The heat generated at the ball piston/test sleeve interface, despite reasonable Hertzian stress levels, caused "smearing" failure of the sleeve wall shortly after the tests were started. Material was actually removed from the cylinder walls and redeposited. A distinct wear pattern was visible on the sleeve and most tests were stopped because the ball seized in the sleeve on the built-up material.
Lubrication solved the problem. The silicon nitride ball ran smoothly in the M2 tool steel sleeve. Test durations of 100 minutes at 200 psi and 800 RPM and 60 minutes at 400 psi and 800 RPM were achieved with no visible wear on sleeve or ball. Figure 2 shows the sleeve bore after the test. In addition, leakage was greatly reduced.

An Alumina ball was successfully run for 10 minutes at 400 psi and 800 RPM as well in a lubricated M2 tool steel sleeve. The sleeve and ball showed minimal signs of wear. Alumina is heavier than silicon nitride, but is much less expensive, and is a viable option for compressor, pump, and motor applications.
A 20 minute test at 400 psi and 800 RPM was run with a chrome steel ball on a lubricated M2 tool steel sleeve. The test was successful but indications of wear were observed. It is likely that the lower modulus of steel caused more deformation of the ball, resulting in a wider contact area, and some cylinder wear indicated as "fogging" of the shiny M2 sleeve surface. The ball also showed fine scratching in a directional pattern, and steel removed from the ball was seen in the lube oil. It is clear that the steel ball would not be acceptable for long term operation.

After this series of tests it is clear that lubrication must be used for the design to work as a compressor or engine with conventional materials. Without lubrication of some kind, the localized heat at the rubbing contact is too great even for high temperature resistant metals and coatings. It may be possible, for compressor/motor/pump applications, to use a ball piston made of some "high-tech" self-lubricating material, such as graphite-impregnated metal or a dimensionally stable and lubricious plastic. These materials may be investigated in the future. For an engine, however, the higher temperature requirements would preclude such materials, and oil lubrication is likely to be the best approach.

It was also found that oil lubrication can greatly improve machine efficiency by virtually eliminating rubbing friction and reducing leakage. Lubrication increases mechanical efficiency from approximately 85% to approximately 97%. Most of this improvement is due to friction reduction. Results indicate that the lube oil produces a hydrodynamic bearing layer at the contact region, resulting in negligible friction coefficient. If this is true, cylinder surface hardness is no longer a great concern, and special coatings and treatments are unnecessary.
Using a stiff ceramic ball with lubrication should work well in a compressor or an engine as long as the lubrication system is properly designed. High speed engines will require a silicon nitride ball to minimize centrifugal loads at high speeds. It is likely that materials other than M2 tool steel could be used as a cylinder material with proper lubrication, such as conventional cast iron and chrome plated iron or steel.
CONCLUSIONS
Analyses based on the design assumptions showed that the ball piston engine has potential for achieving higher efficiency than piston internal combustion engines. In addition, subscale tests have shown that critical leakage and friction characteristics are consistent with design assumptions. Thus, the feasibility of this new engine concept based on ball pistons has been proven.
A new approach to kinematic design has been devised to eliminate friction contributions from inertial forces in the engine. On the other hand, conventional carburetion/induction and exhaust systems are applicable to the new engine. Some material problems were encountered in subscale testing, indicating that more detailed material selection was warranted. The material selection has been done in anticipation of additional subscale tests to extend the range of speed and duration of simulated operation. Baseline material for testing is M2 tool steel.
Shortly after cylinder material selection is verified in subscale tests, fabrication and testing of a prototype engine will be undertaken. The prototype will be used to finalize design details such as thermal design, transient operation, starting, and cylinder wall treatments with actual combustion environment.
The new design concept can be immediately applied to compressor and pump applications in parallel with further engine development. The concept holds immediate promise for high efficiency and low cost in these applications, where temperatures and loads are more benign and lower cost materials can be used.

REFERENCES

Dale, T.W.,"Spherical Piston Radial Action Engine", U.S. Patent #5,419,288, May 30, 1995.
Avallone, E.A. and Baumeister, T. III,"Marks' Standard Handbook for Mechanical Engineers", Ninth edition, McGraw-Hill, New York, 1987.
Richards, T.D.,"The Hanes Engine", informational report, copyright 1994.
Ashley, S.,"A New Spin on the Rotary Engine", Mechanical Engineering, April 1995, p80-82.
Bloch, H.P.,"A Practical Guide to Compressor Technology", McGraw-Hill, New York, 1996.
Anon.,"GAUSS Volume I, System and Graphics Manual", Aptech Systems, Inc., Maple Valley, WA, July 18, 1994.
Heywood, J.B.,"Internal Combustion Engine Fundamentals", Mcgraw-Hill, New York, 1988.

8.Internate

2010-06-22T10:21:00.000-07:00

i am using the fill surface tool in solid works............
it works so awesome...........

After joining the surfaces..............

12th HSC std result for Mahrashtra state.

2010-05-24T21:10:00.000-07:00

Maharashtra Board Class 12 HSC Results 2010

The results for the Higher Secondary Certificate (HSC) for Class XII or Std 12th held in Maharashtra will be declared on May 25th 2010 at 11AM.

Students who appeared for the Maharashtra HSC exams in 2010 will be able to check their results online after 11AM at the official Maharashtra Exam site. Maharashtra HSC results will be available at http://mahresult.nic.in/ after 11AM on Tuesday.

Students will require to have their hall ticket roll numbers in order to view their HSC exam results online. Students can also check their exam results by visiting http://results.maharashtraeducation.net/ or http://www.msbshse.ac.in/.

The HSC results will be declared for the Arts, Science and Commerce streams for students who appeared for the exams in February 2010. However, students will get their marksheets from their colleges only on May 31st after 3PM.

The online results are being declared a week earlier than the actual results is handed out in order to allow students to better plan out their future course of actions. We wish all the students best of luck for their exam results.

“NETWORK SECURITY”

2010-05-14T13:08:00.001-07:00

ABSTRACT

Today's world is a networked world in which everyone is entering into outside world for mainly, for communication purpose. This is possible only due to the internet facility whose access is an immense source of information. Apart from being a source, we need to have secure communication channel through which the information passes. Loss of irreplaceable data is very real threat, especially for the business owners. They need to communicate with their vendors, employees, customers who are far away from each other. At this stage, Internet will be the easiest & fast source of information exchange for them. So, to keep this information safe & secure, a need felt to provide security to the Internet.

Network security is a complicated subject, historically only tackled by well-trained and experienced experts. Network, as it is vast, interconnected & complicated structure requires lot of understanding about each component, which is a part of it. So, Network Security tests our stamina about keeping the network as safe, secure as possible. As more and more people become ``wired'', an increasing number of people need to understand the basics of security in a networked world. Network Security ensures the reliability, flexibility of an network's working so as to make smooth communication through the network. Any organization, before taking Internet access, first think of firewall.

Some history of networking is included, as well as an introduction to TCP/IP and internetworking. Some points are also concerned to the types of threats, from which one should be aware of, & providing protection against it.

INDEX

1. INTRODUCTION

2. SECURED COMMUNICATION

3. NEED OF SECURITY

THREATS TO SECURITY
4. MECHANISMS OF SECURITY
5. CRYPTOGRAPHY
SECRET - KEY ENCRYPTION
PUBLIC - KEY ENCRYPTION

FIREWALL AND INTERNET ACCESS.

FIREWALL ARCHITECTURE
PACKET - LEVEL FILTERS.
SECURITY AND PACKET FILTER MECHANISM.
ACCESSING SERVICES THROUGH A FIREWALL.

NETWORK SECURITY TOOLS
CONCLUSION
REFERENCES

INTRODUCTION

Network

A ``network'' has been defined as

``Any set of interlinking lines resembling a net, a network of roads || an
interconnected system, a network of alliances.''

This definition suits our purpose well:

A computer network is simply a system of interconnected computers.

Security

Security by the name itself is very important for any individual, a machine or also in a network like the locks to help tangible property secure, computers and data networks need provisions that help keep the information secure. Security in an Internet environment is both important and difficult. It is important because information has a significant value -information can be bought and sold directly or used indirectly to create new products and services that yield high profits. Security in an internet is difficult because involves understanding when and how participating users, computers, services and networks can trust one another, as well as understanding the technical details of network hardware and protocols.

As the Internet is becoming more complex day by day security administrators face the risk of being attacked by external intruders that may

Read Access - Read or copy confidential information.
- Write Access - Write to network or perhaps infect the system with the system with viruses and Trojan horses.
Denial of Service - Deny authorized users normal network services.

A single computer can compromise the security of entire network. To guard against such threats the security of distributed system, security
policies must be adapted and security mechanisms must be employed to implement security policies.

Threats

There are four classes of Security threats to computers systems. These are

Leakage
Tempering
Resource stealing
Vandalism

Thus to guard against threats to the security of distributed system, security policies as well as security mechanisms must be employed thereby providing a secure communication link for a data transmission between interconnected host computer systems of network.

SECURED COMMUNICATION

Suppose two persons A & B are communicating. Both of them make sure that contents delivered are not altered by an intruder and are being transferred between them only. The following considerations below reflect these desirable properties of secure communication.

SECRECY

Only the sender and the intended receiver should be able to understand the contents of the transmitted message. Because eavesdroppers may intercept the message been somehow "encrypted" so that an intercepted message can be "decrypted" by an interceptor. For example, A might also want the mere fact that she's communicating with B to be a secret.

AUTHENTICATION

Here both the sender and receiver need to confirm the identity of the other party involved in the communication- to confirm that the other party is indeed who or what they claim to be.

For example - If A receives mail from B, in order to know that it has been sent by the B only A needs some authentication; likewise in network there are authentication protocols.

MESSAGE INTEGRITY

Here the sender and receiver want to ensure that apart from authentication the content of their communication is not altered, either maliciously or by accident in transmissions.

NEED FOR NETWORK SECURITY

Most of the security problems are intentionally caused by malicious people trying to gain some benefit or harm some one enforcing the security administrators to keep network free from programming errors. Thus in turn involves out mastering often intelligent, dedicated and sometimes well-funded adversaries and hence need for security rises. The issue is that network security calls for protections against malicious attack by hackers and intruders, but security is also associated with controlling and authorization mechanisms and the prevention of the effects of errors and equipment failures.

All communication over Internet uses the transmission control protocol /Internet protocol (TCP/IP). TCP/IP allows information to be send from one computer to another computer through variety of intermediate computer and separate network before its destination.

The great flexibility of TCP/IP has led to its worldwide acceptance as the basic Internet and Intranet communications protocol. At the same time, the fact that TCP/IP allows information to pass through intermediate computers makes it possible for a third party to interface with communications in the following ways:

Eavesdropping. Information remains intact, but its privacy is compromised .For example, someone could learn your credit card number, record a sensitive conversation, or intercept classified information.
Tampering. Information in transit is changed or replaced and then sent on to the recipient. For example, someone could alter an order for goods or change a person's resume.
Impersonation. Information passes to a person who poses as the indirect recipients. Impersonation can take two forms
- Spoofing: - A person can pretend to be someone else.
  For example, a person can pretend to have the email address jdoe@mozilla.com <mailto:jdoe@mozilla.com>, or a computer can identify itself as a site called www.mozilla.com http://www.mozilla.com
  
  when it is not. This type of impersonation is known as spoofing.

Misrepresentation: - A person or organization can misrepresent itself. For example, suppose the site www.mozilla.com http://www.mozilla.com pretends to be a furniture store when it is really just a site that takes credit-card payments but never sends any goods.

Packet Sniffing; - A packet snifter is a program running in a network-attached device that passively receives all data link layer frames passing by network device's interface. In broadcast environment like the Ethernet LAN the packet snifter receives all frames being transmitted from all hosts on the LAN. These frames can then be passed on to application programming that extract application level data.

MECHANISMS FOR NETWORK SECURITY

Internet security problems can be divided into three broad sets.

AUTHENTICATION MECHANISMS

Authentication mechanisms solve the problem of verifying identification. In centralized multi-user systems, the user's identity can be authenticated by a password check at the start of each interactive session. In distributed systems, authentication is the means by which the identities of servers and clients are reliably established. The mechanism used to achieve this is based on possession of encryption keys.

PRIVACY MECHANISMS

Encryption can also handle the problem of privacy. If a sender and receiver both use public key encryption scheme, the sender can guarantee that the intended receiver can read a message .To do so, the sender uses the receiver's public key to encode the message and the receiver uses its private key to decode the message. Because only the intended receiver has necessary private key, no other party can decode the message.

ACCESS CONTROL MECHANISMS

Mechanisms that control Internet access handle problem of screening of particular network or an organization from an unwanted communication. Such mechanism can help to prevent outsiders from obtaining information, changing information, or disrupting communication on an organization 's internal Internet.

CRYPTOGRAPHY

INTRODUCTION

"The art of devising a ciphers i.e. converting the plaintext into coded format & then decoding it" refers to cryptography. Here message to be encrypted are known as plain text & are transformed by a function parameterized by a key. The output of encryption process is known as 'cipher text' and is often transmitted by a messenger .At the receiver its decrypted with help of decryption key and the original message is retrieved.

To encrypt information we transform it in such way that it cannot understand by anyone except the intended recipient who posses the means to reverse the transformation. Computer encryption techniques fall into two main classes-

which useful implementation security, which can be used without much impact on the method of encryption.

SECRET KEY ENCRYPTION

This method is used for transformation of secret information. In this method applying an agreed encryption function to the plain text with secret key encrypts a message. Decryption is achieved by applying inverse function to the cipher text using the same key, to produce the original plain text. Since the keys are kept secret, the encryption and decryption function need not be secret. Before communication can take place both the sender and receiver must acquire the secret key.

PUBLIC KEY ENCRYPTION

In this method each potential recipient of message makes a pair of keys, Ke & Kd and keeps the decryption key Kd a secret. The encryption key Ke can be made known publicly for use by anyone who wants to communicate. This method is based on use of any-way function to define the relation between the two keys, so that it is very hard to determine Kd from knowledge of Ke. Thus it avoids the need for transmission of secret keys between principles.

FIREWALLS AND INTERNET ACCESS

The Firewalls defines as "a system or group of systems that enforces an access control policy between two networks." In the context of home networks, a firewall typically takes one of two forms:

Software firewall - specialized software running on an individual computer,

Network firewall - a dedicated device designed to protect one or more computers.

A single technique has emerged as the basis for Internet access control .The technique places a block known as Internet firewall at the entrance to the part of Internet to be produced .For example, an organization can place firewall at its connection to the global Internet to protect it from unwanted access .A firewall partition has two regions , Informally referred as inside & outside.

Firewall Architecture

There are lots of ways to structure your network to protect your systems using a firewall. If you have a dedicated connections to the Internet through a router, you could plug the router directly into your firewall system. Or, you could go through a hub to provide for full access servers outside your firewall.

Dial-up Architecture

You may be using a dialup service like an ISDN line. In this case you might use a third network card to provide provide a filtered DMZ. This gives you full control over your Internet services and still separates them from your regular network.

Single Router Architecture

If there is a router or cable modem between you and the Internet. If you own the router you could setup some hard filter rules in the router. If this router is owned by your ISP so you may not the have the needed controls. You can ask your ISP to put in filters.

Firewall with Proxy Server

If you need to monitor where users of your network are going and your network is small, you can intergrate a proxy server into your firewall. ISP's some times do this to create interest list of their users to resell to marketing agencies.

You can put the proxy server on your LAN as will. In this case the firewall should have rules to only allow the proxy server to connect to the Internet for the services it is providing. This way the users can get to the Internet only through the proxy.

Redundent Internet Configuration

If you are going to run a service like YAHOO or may be Slash Dot you may want to make your system by using redundant routers and firewalls. (Check out the High Availability HowTo.) By using a round-robin DNS techniques to provide access to multiple web servers from one URL and multiple ISP's, routers and firewalls using High Availability techniques you can create a 100% uptime service.

It is easy to let your network get out of hand. Keep control of every connection. It only takes a user with a modem to compromise your LAN.

Packet-level filters:

Many commercial routers offer a mechanism tact augments normal routine and permits a manager to further control packet processing . Packet filters mechanism requires the manager to specify how the router should dispose of each datagram . When Datagram first arrives, the router passes the Datagram through its packet filter before performing any other processing . if the filter rejects the Datagram the router drops it immediately. Each router vender is free to choose the capabilities of their packet filter as well as the interface a manager use to configure the filter.

Security and packet filter mechanism:

Packet filtering firewall consists of list of acceptance denial rules . These rules explicitly define which packets will and will not be allowed through the network interface. These rules are based on the specific network layer's source and destination addresses.

Accessing service through a firewall:

An organization can only provide safe access to outside services through a secure computer . Instead of trying to make all computer system organizations secure,an organization usually associates one secure computer with each firewall. It is often called as bastion host.

Bastion host :

A general-purpose computer used to control access between the internal (private) network (intranet) and the Internet (or any other untrusted network). Typically, these are hosts running a flavor of the Unix operating system that has been customized in order to reduce its functionality to only what is necessary in order to support its functions. Many of the general-purpose features have been turned off, and in many cases, completely removed, in order to improve the security of the machine.

To permit safe access, firewall has two conceptual barriers which the figure shows. The outer barrer blocks all incoming traffic except :

Datagrams destined for services on the bastion host that the organization choose

to make available externally,

Datagrams destined for the clients on the bastion host .
The inner barrier blocks the incoming traffic excepts datagrams that originate on the
bastion host.

To understand how the bastion host operates ,consider the FTP service. Suppose a user in the organization needs to access an external FTP server to obtain copy of the file . Because the firewall prevents the user's computer from receiving incoming datagrams , the user cannot run FTP client software directly .Instead, the user must run the FTP clienton the bastion host. after the file has been copied to the bastion host,the user can run file transfer between the bastion host and their local computer .

NETWORK SECURITY TOOLS

Various Tools for the Network Security are existing in this world which can work better& provides reliable communication channel through which information can be safely transmitted from sender to the reciever. These tools are as follows:

SATAN

SATAN, the System Administrator Tool for Analyzing Networks, is a network security analyzer designed by Dan Farmer and Wietse Venema. SATAN scans systems connected to the network noting the existence of well known, often exploited vulnerabilities. For each type of problem found, SATAN offers a tutorial that explains the problem and what can be done.

ipacl

The ipacl package from Siemens. Forces all TCP and UDP packets to pass through an access control list facility. The configuration file allows packets to be accepted, rejected, conditionally accepted, and conditionally rejected based on characteristics such as source address, destination address, source port number, and destination port number. Should be portable to any system that uses System V STREAMS for its network code.

TCP Wrappers

The tcp_wrapper package by Wietse Venema. Formerly called log_tcp. Allows monitoring and control over who connects to a hosts TFTP, EXEC, FTP, RSH, TELNET, RLOGIN, FINGER, and SYSTAT ports. Also includes a library so that other programs can be controlled and monitored in the same fashion.

Some more no. of tools are as follows:

Logdaemon
Portmap
Rpcbind
Sara
Scanssh
Securelib
Rpcbind

CONCLUSION

Security is a very difficult topic. Everyone has a different idea of what ``security'' is, and what levels of risk are acceptable. The key for building a secure network is to define what security means to your organization . Once that has been defined, everything that goes on with the network can be evaluated with respect to that policy. Projects and systems can then be broken down into their components, and it becomes much simpler to decide whether what is proposed will conflict with your security policies and practices.

Many people pay great amounts of lip service to security, but do not want to be bothered with it when it gets in their way. It's important to build systems and networks in such a way that the user is not constantly reminded of the security system around him. Users who find security policies and systems too restrictive will find ways around them. It's important to get their feedback to understand what can be improved, and it's important to let them know why what's been done has been, the sorts of risks that are deemed unacceptable, and what has been done to minimize the organization's exposure to them.

Security is everybody's business, and only with everyone's cooperation, an intelligent policy, and consistent practices, will it be achievable.

REFERENCES

Computer networks by Andrew Tannenbaum.
Computer networking by John Martin.
Internetworking with TCP/IP by Douglas E.Comer.
http://www.google.com

Bio-Informatics: A computational approach to molecular biology

2010-05-14T13:01:00.001-07:00

What is Bio-informatics?

Bio-informatics is a newly emerging interdisciplinary research area which may be defined as the interface between biological and computational sciences. Thus, the people working in this field in most cases either have a training in biology or computer science, and they learned about the other field by dealing with problems or using the tools of the other one. And although the term 'Bio-informatics' is not really well-defined, you could say that this scientific field deals with the computational management of all kinds of biological information, whether it may be about genes and their products, whole organisms or even ecological systems. Most of the Bio-informatics work that is being done deals can be described as analyzing biological data, although a growing number of projects deal with the organization of biological information. As a consequence of the large amount of data produced in the field of molecular biology, most of the current Bio-informatics projects deal with structural and functional aspects of genes and proteins. Many of these projects are related to the Human Genome Project.

First, the data produced by the thousands of research teams all over the world are collected and organized in databases specialized for particular subjects. Well-known examples are: GDB (Genome Data Base). , SWISS-PROT , GenBank , and PDB (Protein Data Bank). In the next step, computational tools are needed to analyse the collected data in the most efficient manner.

One example for such an integration effort is the GeneCards encyclopedia,. This resource contains data about human genes, their products and the diseases in which they are involved. (a process similar to "data mining").

Bio-Informatics: A computational approach to molecular biology

Bio-informatics has been the latest buzzword in the business and scientific community, the hype for this emerging field has been increasing day by day, more and more educational organizations have already added this name to their academic profiles.

If you were a computer-programmer, bio-informatics skills would enable you to make software for biological applications and if you were biologist, bio-informatics would probably be the best tool to speed up your work just by using a computer with an internet connection. On an over all, bio-informatics is a very important tool for any one who is serious about computing biological processes.

"Bio informatics is a science of solving biological problem using a mathematical and computational approach."

Many of us confuse Bio-informatics with that of Bio-computing; fundamentally it's a complete different field. Bio-computing or molecular computing is applying biology to solve complex and computationally almost impossible problems using biology, the best example is the famous 'Traveling sales man problem' which was treated computationally impossible to solve.// Bio-informatics a very new field, it has been hardly five years since this science has come into existence in a common man's life. It is a mathematical and computational approach, you need to know mathematics to actually understand bio-informatic application. Fundamental knowledge of molecular biology is also necessary to learn bio-informatics. Molecular biology is a branch of biology which primarily deals with functions, characteristics and structures of mainly three major macro-molecules DNA,RNA and Proteins.

Protecting Bio-informatics Tools :

Bio-informatics involves the use of computer software to gather, sort, and analyze biological data – often with a goal of finding "drug gable targets" for pharmaceutical R&D. It has not always been clear which form of legal protection (primarily, copyright or patents) provides the best value for a bio-informatics product, given, in particular, the considerable doubt and confusion in the European Union as to the validity of software patents. However, recent developments in the European Union with respect to software patents, coupled with industry trends in the US as well as Europe, suggest that bio-informatics companies should give patent protection a very close look.

Genomes to Life

The revolution in biology triggered by the Human Genome Project now promises far-reaching benefits.

Today, scientists have in hand the complete DNA sequences of genomes for many organisms — from microbes to plants to humans. The U.S. Department of Energy's Genomes to Life program will use the new genomic data and high-throughput technologies for studying the proteins encoded by the genome to explore the amazingly diverse natural capabilities in microbes. These can be exploited to help solve DOE mission challenges in

Energy production and global climate change mitigation, and
Environmental cleanup
- Underlying goals of the Genomes to Life program that will enable these benefits are to Identify the protein machines that carry out critical life functions,
Characterize the gene regulatory networks that control these machines,
Explore the functional repertoire of complex microbial communities in their natural environments to provide a foundation for understanding and using their remarkably diverse capabilities to address DOE missions, and Develop the computational capabilities to integrate and understand these data and begin to model complex biological systems.

Features

Data Integration
- Data export to excel and other formats
- Import and integration from diverse sources:
  - Sequence data: Genbank, FASTA formatted files, Swissprot format
  - Gene Ontology
  - PDB
  - KEGG
Method Integration
- Methods from various disciplines for analysis of
  - Sequence
  - Structure
  - Expression data
  - Taxonomy and Phylogeny
  - Metabolic pathways
- Workflows
- Automatic checking of data compatibility
- Background execution of workflows
- Available methods:
  - Bio-informatics
    - Blast and Psi-Blast
    - Sequence repeat detection
    - Function analysis for cluster of sequences
    - Match sequence profiles and regular expressions
    - Expression matrix processing: Completion, Normalization, Filtering and Masking
    - Mapping of expression data to metabolic pathways, Gene Ontology
    - Metabolic pathway reconstruction
  - General
    - Vector operations
    - Sorting
    - Shuffling
    - Statistics (average, mean, etc.)
Visual Orientation
- Graphical workflow representation
- Drag n drop workflow construction
- Hierarchical tabular viewers
- Diverse graphical viewers for biological data and workflow results
Advantages
- Shallow learning curve thanks to visual programming
- Unified data structure
- Expandability through script language (python)
- Scalability from desktop to corporation
- Company-wide sharing of results and methods
Daphnia Genomics Consortium:

The Daphnia Genomics Consortium (DGC) is an international network of investigators committed to mounting the freshwater crustacean Daphnia as a model system for evolutionary / ecological genetics and genomics

Dicty WorkBench:

Dictyostelium discoideum genome annotation and analysis portal; specialized Dictyostelium sequence and function annotaton database.

Ensembl Genome Browser:

Website, MySQL server and perl API access to software system which produces and maintains automatic annotation on eukaryotic genomes.

MIPS:

Munich Information Centre for Protein Sequences projects include: fungal genome analysis, plant genome Bio-informatics, structural genomics, proteomics and genome annotation; databases include: Sputnik, MosDB, and PEDANT.

Parasite-Genome:

Parasite genome databases and genome research resources.

TCAG Genome Resource Facility:

Genomic and cDNA library screening (human, mouse, dog, pig) is provided free to Canadian academic researchers with a nominal clone retrieval fee; includes Research Genetics, NIA/NIH and RIKEN cDNAs.

SARS Genome Browser Gateway:

Provides a rapid and reliable display of any requested portion of the SARS genome at any scale, together with dozens of aligned annotation tracks.

Integrated Bio-informatics Software

GCG :-

GCG is one of the earliest integrated Bio-informatics system. It maintains more than 70 Bio-informatics data analysis tools, which are based on published algorithms from fields of mathematical and computational biology. In additions to running these programs individually, GCG allows the data flow among them. By using these tools, scientists can accomplish the following tasks:

Sequence Comparison
Database Searching and Retrieval
DNA/RNA Secondary Structure Prediction
Editing and Publication
Evolution Analysis
Fragment Assembly
Gene Finding and Pattern Recognition
Importing and Exporting Files in Different Formats
Mapping
Primer Selection
Protein Analysis
Translation

ICBR maintains a GCG server and keeps updated with NCBI and EBI databases. We support command line GCG. It gives the users quick and reliable analysis results. Regular GCG workshops are held once every year.

Biocatalog :-

The Biocatalog is a software directory of general interest in molecular biology and genetics. lists the databases DNA, Proteins, Alignments, Genomes, Genetic, Mapping, Molecular Evolution, Molecular graphics, databases, server.

BioTools (GeneTool & PepTool) :-

BioTools Suite includes GeneTool and PepTool for nucleotide and peptide sequence analysis respectively. Compared to GCG, BioTools has the most user-friendly interface. It covers almost all routine Bio-informatics jobs while the analysis function is less powerful than GCG. However, we find BioTools is a very good software for Bio-informatics novices and basic analysis. It's much better developed and more reliable than those freeware you can get from the Internet. Here we list some features of BioTools.

Chromatogram Analysis and Sequence Assembly
Database Reference Search and BLAST Search
Multiple Alignment
Vector Construct
Primer Design
Biochemistry Statistics of Nucleotide & Protein Sequence
Translation
Restriction Map

BioEdit
In addition to a sequence alignment editor, BioEdit is also connected with a wide range of free Bio-informatics programs on the Internet. The topics cover from BLAST search to promoter prediction. If you want to get some freeware, BioEdit is a good one you may want to have a look at.

Real world applications of Bio-informatics:

1. Molecular medicine :--

1.1 More drug targets

At present all drugs on the market target only about 500 proteins. With an improved understanding of disease mechanisms and using computational tools to identify and validate new drug targets, more specific medicines that act on the cause, not merely the symptoms, of the disease can be developed. These highly specific drugs promise to have fewer side effects than many of today's medicines.

1.2 Personalised medicine

Clinical medicine will become more personalised with the development of the field of pharmacogenomics. This is the study of how an individual's genetic inheritence affects the body's response to drugs. At present, some drugs fail to make it to the market because a small percentage of the clinical patient population show adverse affects to a drug due to sequence variants in their DNA.

1.3 Preventative medicine

With the specific details of the genetic mechanisms of diseases being unravelled, the development of diagnostic tests to measure a persons susceptibility to different diseases may become a distinct reality. Preventative actions such as change of lifestyle or having treatment at the earliest possible stages when they are more likely to be successful, could result in huge advances in our struggle to conquer disease.

1.4 Gene therapy

In the not too distant future, the potential for using genes themselves to treat disease may become a reality. Gene therapy is the approach used to treat, cure or even prevent disease by changing the expression of a persons genes. Currently, this field is in its infantile stage with clinical trials for many different types of cancer and other diseases ongoing.

2. Microbial genome applications :-

2.1 Waste cleanup

Deinococcus radiodurans is known as the world's toughest bacteria and it is the most radiation resistant organism known. Scientists are interested in this organism because of its potential usefulness in cleaning up waste sites that contain radiation and toxic chemicals.

2.2 Climate change

Increasing levels of carbon dioxide emission, mainly through the expanding use of fossil fuels for energy, are thought to contribute to global climate change. Recently, the DOE (Department of Energy, USA) launched a program to decrease atmospheric carbon dioxide levels. One method of doing so is to study the genomes of microbes that use carbon dioxide as their sole carbon source.

2.3 Alternative energy sources

Scientists are studying the genome of the microbe Chlorobium tepidum which has an unusual capacity for generating energy from light

2.4 Biotechnology

The archaeon Archaeoglobus fulgidus and the bacterium Thermotoga maritima have potential for practical applications in industry and government-funded environmental remediation. These microorganisms thrive in water temperatures above the boiling point and therefore may provide the DOE, the Department of Defence, and private companies with heat-stable enzymes suitable for use in industrial processes

2.5 Antibiotic resistance

Scientists have been examining the genome of Enterococcus faecalis-a leading cause of bacterial infection among hospital patients. They have discovered a virulence region made up of a number of antibiotic-resistant genes that may contribute to the bacterium's transformation from a harmless gut bacteria to a menacing invader. The discovery of the region, known as a pathogenicity island, could provide useful markers for detecting pathogenic strains and help to establish controls to prevent the spread of infection in wards.

3. Agriculture :-

The sequencing of the genomes of plants and animals should have enormous benefits for the agricultural community. Bioinformatic tools can be used to search for the genes within these genomes and to elucidate their functions. This specific genetic knowledge could then be used to produce stronger, more drought, disease and insect resistant crops and improve the quality of livestock making them healthier, more disease resistant and more productive.

4. Animals

Sequencing projects of many farm animals including cows, pigs and sheep are now well under way in the hope that a better understanding of the biology of these organisms will have huge impacts for improving the production and health of livestock and ultimately have benefits for human nutrition

5. Comparative studies

Analysing and comparing the genetic material of different species is an important method for studying the functions of genes, the mechanisms of inherited diseases and species evolution. Bioinformatics tools can be used to make comparisons between the numbers, locations and biochemical functions of genes in different organisms.

ARTIFICIAL RAIN

2010-05-11T09:26:00.001-07:00

दोनशे लिटर क्षमतेची रिकामी टाकी, तिच्या एका तोंडाला लावण्याची लोखंडी जाळी, तिच्या आत हवा जाण्यासाठी तयार केलेली नळी, तापमान-वारा-आर्द्रता मोजणारे मापक... कोठेही सहज उपलब्ध होणाऱ्या या साधनांद्वारे पुण्यातील एका अभियंत्याने कृत्रिम पाऊस पाडणारे यंत्र तयार केले आहे. या यंत्रात भुश्‍श्‍याच्या विटा किंवा गोवऱ्या किंवा लाकडे घालून पेटविले आणि नंतर त्यात मीठ टाकल्यास प्रयोगानंतरच्या २४ तासांत पाच मिलिमीटरपर्यंत पाऊस होतो, असा दावा त्यांनी केला आहे.

डॉ. राजा मराठे हे या अभियंत्याचे नाव. मुंबईमधील "इंडियन इन्स्टिट्यूट ऑफ टेक्‍नॉलॉजी'चे ते पदवीधर आहेत आणि अमेरिकेच्या राईस विद्यापीठातून पीएच. डी. मिळविली आहे. भारताने बनविलेल्या "परम' या पहिल्या महासंगणकाच्या विकासकार्यात त्यांचा सहभाग होता. सामाजिक कार्यातही अग्रेसर असलेल्या डॉ. मराठे यांनी गेल्या वर्षी नांदेड जिल्ह्यातील सुजलेगाव येथे कृत्रिम पावसाबाबतचे काही प्रयोग केले. अशा दहा प्रयोगांत नऊ वेळा पाऊस झाल्याचे ते सांगतात. सुजलेगाव परिसरातील अन्य गावांतही त्यांनी हा प्रयोग केला आहे.

असा करतात वरुणयंत्राचा कमी खर्चिक प्रयोग
पुणे - ""पावसाने दडी मारल्यास शेतीचे मोठे नुकसान होते. अर्थव्यवस्थेलाही त्याचा फटका बसतो. हे टाळण्यासाठी कृत्रिम पाऊस पाडण्यावर भर दिला पाहिजे,'' असे मत ज्येष्ठ अभियंते आणि कृत्रिम पाऊस पाडणाऱ्या "वरुण यंत्रा'ची निर्मिती करणाऱ्या डॉ. राजा मराठे यांनी व्यक्त केले आहे.

कृत्रिम पावसाचे अनेक प्रयोग जगभर होत असतात. त्यांपैकी सर्रास केला जाणारा प्रयोग म्हणजे विमानाद्वारे ढगात सिल्व्हर आयोडाईडची फवारणी करणे. या खेरीज खास बनविलेल्या रॉकेटद्वारा किंवा तोफांद्वाराही सिल्व्हर आयोडाईडची फवारणी केली जाते. बहुतेक ठिकाणी हे प्रयोग सरकारकडून केले जातात, शिवाय त्यांचा खर्चही अधिक असतो. महाराष्ट्रात काही वर्षांपूर्वी बारामतीमध्ये हा प्रयोग झाला आहे.

डॉ. मराठे यांनी "वरुण यंत्रा'चा छोटेखानी प्रयोग सुरू केला आहे. ते म्हणाले, ""कृत्रिम पावसाच्या कोणत्याही प्रयोगात ढगापर्यंत उत्प्रेरक नेले जाते. पाऊस पडण्यासाठी ढगा मधील पाण्याचे छोटे छोटे थेंब एकमेकांकडे आकर्षित होणे महत्त्वाचे असते. त्यासाठी उत्प्रेरकाची गरज असते. मिठाचे सूक्ष्म कण हे उत्प्रेरकासारखे काम करतात. ढगामध्ये विमानाने मिठाची फवारणी शक्‍य नसल्यास जमिनीवर भट्टी करून त्यात मिठाचे कण टाकल्यास ते ढगापर्यंत पोहोचू शकतात. हे तत्त्व वापरून मी प्रयोग केले आहेत. हा प्रयोग कोणालाही सहजगत्या करता येऊ शकतो. त्यामुळे प्रत्येक गावात तो होऊ शकेल. तसे झाल्यास पाऊस न पडण्याच्या अडचणीवर मात करता येईल.''

हा प्रयोग करण्यासाठी वातावरण ढगाळ असणे आवश्‍यक आहे. शिवाय प्रयोगाच्या वेळी हवेत चांगला ओलावा (आर्द्रता) असायला हवा आणि वारे नसावेत. पहाटेची किंवा सायंकाळची वेळ प्रयोगासाठी चांगली असल्याचे डॉ. मराठे यांनी सांगितले. या प्रयोगासाठी "आयआयटी'मधील आजी-माजी सहकाऱ्यांनी; तसेच रोहिणी नीलेकणी यांनी मदत केल्याचे त्यांनी सांगितले.

वरुण यंत्राचा प्रयोग कसा करावा?
"वरुण यंत्रा'चे नमुने डॉ. राजा मराठे यांनी तयार केले आहेत. त्याची किंमत २२५० रुपये आहे. सुजलेगाव (ता. नायगाव, जि. नांदेड) येथून ती मिळतील.

हे यंत्र म्हणजे दोनशे लीटर क्षमतेची लोखंडी टाकी आहे. तिच्या दोन्ही बाजूंकडील पत्रे नसतात. त्यामुळे पोकळ असलेल्या या टाकीच्या एका बाजूला लोखंडी गजांची जाळी बसवतात. याच जाळीवर एक सच्छिद्र आडवी नळी बसविली असते. तिच्या मध्यभागी काटकोनातून दुसरी नळी बसवून ती बाहेर काढतात. या नळीला "ब्लोअर' किंवा भाता जोडला जातो. विजेवर चालणारे "ब्लोअर' चालू केल्यास टाकीमध्ये ऑक्‍सिजनचा पुरवठा वाढतो. वीज नसल्यास भाता वापरला तरी चालतो.

यंत्र वापरण्याची कृती
या टाकीत जळण म्हणून लाकडे, गोवऱ्या, भुश्‍श्‍याच्या विटा सहा इंचापर्यंत रचून ठेवाव्यात. त्यानंतर त्यात रॉकेल टाकून पेटवावे. चांगला जाळ पेटल्यानंतर भुश्‍श्‍याच्या गोवऱ्या किंवा लाकडाच्या ढिपल्या दोन फुटांपर्यंत टाकीत टाकाव्यात. त्यानंतर "ब्लोअर'ने किंवा भात्याने जोरात हवा द्यावी. भट्टी चांगली पेटवून वर आगीचा जाळ यायला लागल्या की त्यात सुमारे सहा किलो मीठ (बारीक) थोडे-थोडे टाकत राहावे.

हा प्रयोग करण्यासाठी आकाश ढगाळ असणे, आर्द्रता अधिक असणे आणि वारा नसणे आवश्‍यक आहे. आर्द्रता मापक यंत्र कोणत्याही शाळेत वा कनिष्ठ महाविद्यालयात उपलब्ध असते.

वरुण यंत्राचे तंत्रज्ञान खुले असल्याचे डॉ. मराठे यांनी सांगितले. या यंत्राची नक्कल करण्यास सर्वांना परवानगी असल्याचे त्यांनी सांगितले.

पाऊस पाडा..
पावसासाठी निसर्गाच्या भरवशावरच बसण्यापेक्षा कृत्रिम पावसाचे प्रयोग सर्वांनी करावेत, असे आवाहन डॉ. राजा मराठे यांनी केले आहे. "पाऊस पाडा, पाणी अडवा, पाणी जिरवा' हे धोरण अवलंबले तरच पाण्याबाबत आपण स्वयंपूर्ण होऊ, असे त्यांचे म्हणणे आहे. त्यांनी "राष्ट्रसंत तुकडोजी महाराज स्वय ंपूर्णता केंद्र' स्थापन केले आहे.

अधिक माहितीसाठी संपर्क ः डॉ. राजा मराठे ९९७०४३५७४०, उमाकांत देशपांडे नावंदीकर ९९२२७२४१०३, संतोष देशमुख सुजलेगावकर ९९७०४६३९०२.

लहरी हवामानावर चीनने अशी केली मात
पुणे - चीनच्या शास्त्रज्ञांनी संशोधनाच्या साह्याने आसमानी संकटावर मात केली आहे. गेल्या पन्नास वर्षांहून अधिक काळ चीनचा वायव्य प्रांत कायम दुष्काळाच्या छायेत असे, तर देशाच्या दुसऱ्या भागात पुराचे थैमान येई, अचानक होणाऱ्या गारपिटीमुळे कोट्यवधीचे नुकसान होई, अशा सर्व अस्मानी संकटावर चिनी वैज्ञानिकांनी तोफा आणि रॉकेटचा मारा करून नियंत्रणाची पद्धत शोधली आहे.

चीनमध्ये गेल्या पन्नास वर्षांत हवामान संशोधनासाठी पंचवार्षिक योजना राबविण्यात येतात. १९९० ते २००० या दहा वर्षांत चीनमध्ये सतरा लाख हेक्‍टर जमिनीवरील पिकांचे गारपिटीमुळे नुकसान झाले होते. तर एकट्या बीजिंग शहरात ३१ मे २००५ला झालेल्या गारपिटीमुळे ८७८७ मोटारींचे नुकसान झाले होते. चीनच्या वायव्य प्रांतात अत्यंत तीव्र दुष्काळ असे तर दुसरीकडे आग्नेय चीनमध्ये पुराचे थैमान असे. तर अनेक शहरातील जनजीवन अत्यंत गडद धुक्‍यामुळे विस्कळित होई, या सर्व अस्मानी संकटाचा चीनच्या अर्थव्यवस्थेवर खूप परिणाम होत असे, म्हणूनच हवामानाच्या लहरीपणावर नियंत्रण मिळविणे चीनला अत्यंत गरजेचे झाले होते.

कृत्रिम पाऊस पाडण्यासाठी चीनमध्ये तोफा, रॉकेट लॉंचर आणि विमानाचा वापर करण्यात येतो. जमिनीवरूनच तोफा आणि रॉकेट लॉंचरच्या साह्याने ढगांचे रोपण (क्‍लाऊड सिडींग) केले जाते. याच पद्धतीने १९५२ जिल्ह्यांमध्ये तोफा आणि रॉकेट लॉंचरचा वापर करून पावसाचे प्रमाण वाढविले तर मोठी गारपीट रोखण्यात यश मिळविले. चीनमध्ये हवामानावरील अभ्यासासाठी २००५ या एका वर्षात ३७२१० शास्त्रज्ञ आणि कर्मचारी कार्यरत होते. त्याचबरोबर कृत्रिम पाऊस पाडण्यासाठी ३७ मानवरहित विमाने, ७०७१ तोफा (३७ इंची) आणि ४६८७ रॉकेट लॉंचरचा वापर करण्यात आला. चीनमधील मोठ्या धरणात सतत पाणीसाठा राहावा, त्याचबरोबर दुष्काळी वायव्य चीनमध्ये पावसाचे प्रमाण वाढविण्यासाठी सुमारे दहा लाख विशिष्ट पद्धतीने तयार केलेले तोफगोळे, ८४, ४१६ रॉकेट, सुमारे सातशे किलो सिल्व्हर आयोडाईडचा वापर करण्यात आला. हवामानाच्या अभ्यासासाठी चीनमध्ये २६८ डॉप्लर रडार कार्यरत आहेत.

३७ इंची तोफा आणि रॉकेट लॉंचरचा वापर करून जमिनीवरूनच ढगांचे रोपण करण्याचे तंत्रज्ञान चीनच्या शास्त्रज्ञांनी शोधले आहे. तोफेतून सोडलेला गोळा आकाशात सहा किलोमीटरपर्यंत मारा करू शकतो आणि ढगांची उंची ही तीन ते सात किलोमीटर अशी असते. तर रॉकेट लॉंचर आकाशात आठ किलोमीटर पर्यंत मारा करतो. तोफगोळ्यामध्ये एक ते चार ग्रॅम सिल्व्हर आयोडाईड असते (रॉकेटमध्ये आठ ग्रॅम) ते जेव्हा गोळ्याचा ढगांत स्फोट होतो, तेव्हा तेथे टाकले जाते. तेथे रासायनिक क्रिया होऊन काही वेळातच पाऊस पडण्यास सुरवात होते. चीनच्या उत्तर आणि वायव्य प्रांतात अधिक शंभर टीएमसी पाणी मिळविण्याची योजना आखली होती. दीड लाख चौरस किलोमीटर परिसरातील यलो नदीच्या ९८ हजार चौरस किलोमीटर पाणलोट क्षेत्रात हा पाऊस पाडण्यात आला.

सुजलेगावनजीकच्या आमच्या नावंदी गावात गेल्या वर्षी एके दुपारी डॉ.मराठे तंत्राने कृत्रिम पावसाचा प्रयोग केला. संध्याकाळी साडेसहाच्या सुमारास तीन किलोमीटर परिसरात पाऊस सुरू झाला, तो दीड तास पडला. सोयाबीन, कपाशीच्या पिकांना २० दिवसांपासून पावसाचा ताण पडला होता, कृत्रिम पावसामुळे या पिकांना जीवदान मिळाले.
- उमाकांत देशपांडे- नावंदीकर, सरपंच

जमिनीवर भट्टी पेटवून ढगांपर्यंत क्षार पाठवण्याची पद्धत जगात अनेक ठिकाणी वापरली जाते. या पद्धतीतील पदार्थांचा अभ्यास होणे आवश्‍यक आहे. या पद्धतीबाबत आजही अनेक प्रश्‍न अनुत्तरीत आहेत. "वरुण यंत्राची'ही उपयुक्तता तपासण्यासाठी तांत्रिक सहकार्य आवश्‍यक असल्यास आम्ही ते देऊ.

Indian engineering service

2010-05-09T03:52:00.000-07:00

1. The EXAMINATION shall be conducted according to the following plan:-

Part I-The written examination will comprise two sections-Section I consisting only of objective types of questions and Section II of conventional papers. Both Sections will cover the entire syllabus of the relevant engineering disciplines viz. Civil Engineering, Mechanical Engineering, Electrical Engineering and Electronics & Telecommunication Engineering. The standard and syllabi prescribed for these papers are given in Schedule to the Appendix. The details of the written examination i.e. subject, duration and maximum marks allotted to each subject are given in para 2 below.

Part II-Personality test carrying a maximum of 200 marks of such of the candidates who qualify on the basis of the written examination.

2. The following will be the subjects for the written examination:-

Note: Candidates are advised to read carefully special instruction to candidates for conventional type tests and objective type tests given in Appendix-IV (Part A & Part B) including the procedure regarding filling in the Answer Sheet of objective type tests in the Examination Hall.

3. In the Personality Test special attention will be paid to assessing the candidate's capacity for leadership, initiative and intellectual curiosity, tact and other social qualities, mental and physical energy, powers of practical application and integrity of character.

4. Conventional papers must be answered in English. Question papers will be set in English only.

5. Candidates must write the papers in their own hand. In no circumstances will they be allowed the help of a scribe to write the answers for them.

6. The Commission have discretion to fix minimum qualifying marks in any or all the papers of the examination. The Objective Type papers as contained in Section-I of the Plan of the Examination will be evaluated first and evaluation of the Conventional Type papers contained in Section-II of the Plan of Examination will be done only of those candidates who obtain the minimum qualifying marks in Objective types papers, as fixed by the Commission.

7. Marks will not be allotted for mere superficial knowledge.

8. Deduction up to 5 per cent of the maximum marks for the written papers will be made for illegible handwriting.

9. Credit will be given for orderly, effective and exact expression combined with due economy of words in the conventional papers of the examination.

10. In the question papers, wherever required, SI units will be used.

Category	Section	Subject	Duration	Maximum Marks
I-CIVIL ENGINEERING	I-Objective Papers	General Ability Test (Part A: General English)(Part B: General Studies)	2 Hrs	200
		Civil Engineering Paper I	2Hrs	200
		Civil Engineering Paper II	2Hrs	200
	II-Conventional Papers	Civil Engineering Paper I	3Hrs	200
	II-Conventional Papers	Civil Engineering Paper II	3Hrs	200
	Total			1000
I-Mechanical ENGINEERING	I-Objective Papers	General Ability Test (Part A: General English)(Part B: General Studies)	2 Hrs	200
		Mechanical Engineering Paper I	2Hrs	200
		Mechanical Engineering Paper II	2Hrs	200
	II-Conventional Papers	Mechanical Engineering Paper I	3Hrs	200
	II-Conventional Papers	Mechanical Engineering Paper II	3Hrs	200
	Total			1000
III-Electrical ENGINEERING	I-Objective Papers	General Ability Test (Part A: General English)(Part B: General Studies)	2 Hrs	200
		Electrical Engineering Paper I	2Hrs	200
		Electrical Engineering Paper II	2Hrs	200
	II-Conventional Papers	Electrical Engineering Paper I	3Hrs	200
	II-Conventional Papers	Electrical Engineering Paper II	3Hrs	200
	Total			1000
IV-Electronics & Telecommunication ENGINEERING	I-Objective Papers	General Ability Test (Part A: General English)(Part B: General Studies)	2 Hrs	200
		Electronics & Telecommunication Engineering Paper I	2Hrs	200
		Electronics & Telecommunication Engineering Paper II	2Hrs	200
	II-Conventional Papers	Electronics & Telecommunication Engineering Paper I	3Hrs	200
	II-Conventional Papers	Electronics & Telecommunication Engineering Paper II	3Hrs	200
	Total			1000

NOTE: Candidates will be supplied with standard tables/charts in SI units in the Examination hall for reference purpose, wherever considered necessary.

11. Candidates are permitted to bring and use battery operated pocket calculators for conventional (essay) type papers only. Loaning or inter-changing of calculators in the Examination hall is not permitted.

It is also important to note that candidates are not permitted to use calculators for answering objective type paper (Test book lets). They should not, therefore, bring the same inside the Examination Hall.

12. Candidates should use only International form of Indian numerals (e.g. 1,2,3,4,5,6 etc.) while answering question papers.

SCHEDULE TO APPENDIX I

Standard and Syllabi

The standard of paper in General Ability Test will be such as may be expected of a Engineering/Science Graduate. The standard of papers in other subjects will approximately be that of an Engineering Degree Examination of an Indian University. There will be no practical examination in any of the subjects.

GENERAL ABILITY TEST

Part A: General English. The question paper in General English will be designed to test the candidate's understanding of English and workmanlike use of words.

Part B: General Studies: The paper in General Studies will include knowledge of current events and of such matters as of everyday observation and experience in their scientific aspects as may be expected of an educated person. The paper will also include questions on History of India and Geography of a nature which candidates should be able to answer without special study.

MECHANICAL ENGINEERING

PAPER-I (For both objective and conventional type papers)

1. Thermodynamics, Cycles and IC Engines, Basic concepts, Open and Closed systems. Heat and work. Zeroth, First and Second Law, Application to non-Flow and Flow processes. Entropy, Availability, Irreversibility and Tds relations. Claperyron and real gas equations, Properties of ideal gases and vapours. Standard vapour, Gas power and Refrigeration cycles. Two stage compressor. C-I and S.I. Engines. Pre-ignition, Detonation and Diesel-knock, Fuel injection and Carburation, Supercharging. Turbo-prop and Rocket engines, Engine Cooling, Emission & Control, Flue gas analysis, Measurement of Calorific values. Conventional and Nuclear fuels, Elements of Nuclear power production.

2. Heat Transfer and Refrigeration and Airconditioning. Modes of heat transfer. One dimensional steady and unsteady conduction. Composite slab and Equivalent Resistance. Heat dissipation from extended surfaces, Heat exchangers, Overall heat transfer coefficient, Empirical correlations for heat transfer in laminar and turbulent flows and for free and forced Convection, Thermal boundary layer over a flat plate. Fundamentals of diffusive and connective mass transfer, Black body and basic concepts in Radiation, Enclosure theory, Shape factor, Net work analysis. Heat pump and Refrigeration cycles and systems, Refrigerants. Condensers, Evaporates and Expansion devices, Psychrometry, Charts and application to air conditioning, Sensible heating and cooling, Effective temperature, comfort indices, Load calculations, Solar refrigeration, controls, Duct design.

3. Fluid Mechanics.
Properties and classification of fluids, Manometry, forces on immersed surfaces, Center of pressure, Buoyancy, Elements of stability of floating bodies. Kinematics and Dynamics.
Irrotational and incompressible. Inviscid flow. Velocity potential, Pressure field and Forces on immersed bodies. Bernoulli’s equation, Fully developed flow through pipes, Pressure drop calculations, Measurement of flow rate and Pressure drop. Elements of boundary layer theory, Integral approach, Laminar and tubulent flows, Separations. Flow over weirs and notches. Open channel flow, Hydraulic jump. Dimensionless numbers, Dimensional analysis, Similitude and modelling. One-dimensional isentropic flow, Normal shock wave, Flow through convergent - divergent ducts, Oblique shock-wave, Rayleigh and Fanno lines.

4. Fluid Machinery and Steam Generators.
Performance, Operation and control of hydraulic Pump and impulse and reaction Turbines, Specific speed, Classification. Energy transfer, Coupling, Power transmission, Steam generators Fire-tube and water-tube boilers. Flow of steam through Nozzles and Diffusers, Wetness and condensation. Various types of steam and gas Turbines, Velocity diagrams. Partial admission. Reciprocating, Centrifugal and axial flow Compressors, Multistage compression, role of Mach Number, Reheat, Regeneration, Efficiency, Governance.

MECHANICAL ENGINEERING PAPER – II
(For both objective and conventional type papers)

5. THEORY OF MACHINES:
Kinematic and dynamic analysis of planer mechanisms. Cams. Gears and gear trains. Flywheels. Governors. Balancing of rigid rotors and field balancing. Balancing of single and multicylinder engines, Linear vibration analysis of mechanical systems. Critical speeds and whirling of shafts Automatic controls.

6. MACHINE DESIGN :
Design of Joints : cotters, keys, splines, welded joints, threaded fasteners, joints formed by interference fits. Design of friction drives : couplings and clutches, belt and chain drives, power screws.
Design of Power transmission systems : gears and gear drives shaft and axle, wire ropes.
Design of bearings : hydrodynamics bearings and rolling element bearings.

7. STRENGTH OF MATERIALS
Stress and strain in two dimensions, Principal stresses and strains, Mohr’s construction, linear elastic materials, isotropy and anisotropy, stress-strain relations, uniaxial loading, thermal stresses. Beams : Bending moment and shear force diagram, bending stresses and deflection of beams. Shear stress distribution. Torsion of shafts, helical springs. Combined stresses, thick-and thin-walled pressure vessels. Struts and columns. Strain energy concepts and theories of failure.

8. ENGINEERING MATERIALS :
Basic concepts on structure of solids. Crystalline maferials. Detects in crystalline materials. Alloys and binary phase diagrams. Structure and properties of common engineering materials. Heat treatment of steels. Plastics, Ceramics and composite materials. Common applications of various materials.

9. PRODUCTION ENGINEERING :
Metal Forming : Basic Principles of forging, drawing and extrusion; High energy rate forming; Powder metallurgy.
Metal Casting : Die casting, investment casting, Shall Moulding, Centrifugal Casting, Gating & Riser design; melting furnaces.
Fabrication Processes : Principles of Gas, Arc, Shielded arc Welding; Advanced Welding Processes, Weldability: Metallurgy of Welding.
Metal Cutting : Turning, Methods of Screw Production, Drilling, Boring, Milling, Gear Manufacturing, Production of flat surfaces, Grinding & Finishing Processes. Computer Controlled Manufacturing Systems-CNC, DNC, FMS, Automation and Robotics.
Cutting Tools Materials, Tool Geometry, Mechanism of Tool Wear, Tool Life & Machinability; Measurement of cutting forces. Economics of Machining. Unconventional Machining Processes. Jigs and Fixtures. Fits and tolerances, Measurement of surface texture, Comparators Alignment tests and reconditioning of Machine Tools.

10. INDUSTRIAL ENGINEERING :
Production Planning and Control : Forecasting - Moving average, exponential smoothing, Operations, scheduling; assembly line balancing, Product development, Break-even analysis, Capacity planning, PERT and CPM.
Control Operations : Inventory control ABC analysis, EOQ model, Materials requirement planning. Job design, Job standards, Work measurement, Quality Management - Quality analysis and control. Operations Research : Linear Programming - Graphical and Simplex methods, Transportation and assignment models. Single server queueing model.
Value Engineering : Value analysis for cost/value.

11. ELEMENTS OF COMPUTATION :
Computer Organisation, Flow charting, Features of Common computer Languages - FORTRAN, d Base III, Lotus 1-2-3, C and elementary Programming.

Book List for Mechanical Engineering IES Exam

SUBJECT	AUTHOR
Engineering Thermodynamics	PK Nag
IC Engine	ML Mathur and RP Sharma
Gas Turbine and Propulsive Systems	PR Khajuria & SP Dubey
Fluid Mechanics	Modi & Seth RK Bansal
Compressible Flow	SM Yahya
Heat and Mass Transfer	JP Hollman RC Sachdeva
Refrigeration and Air Conditioning	CP Arora Domkundwar
Fluid Machinery	Jagdish Lal RK Bansal
Theory of Machines	RS Khurmi Malik & Ghosh
Mechanical Vibration	Grover
Machine Design	Shigley VB Bhandari
Material Science	WD Callister IP Singh
Production Engineering	Kalpkjian Schmid Amitabh Ghosh & AK Malik
Industrial Engineering	O P Khanna Buffa & Sarin
Operations Research	Kanti Swarup
Strength of Materials	Gere & Timoshenko BC unamia Sadhu Singh

Gate examination

2010-05-09T03:49:00.001-07:00

What is GATE ?

The Graduate Aptitude Test in Engineering (GATE) is an all-India examination administered and conducted in eight zones across the country by the GATE Committee comprising faculty from Indian Institute of Science, Bangalore and seven Indian Institutes of Technology on behalf of the National Coordinating Board - GATE, Department of Education, Ministry of Human Resources Development (MHRD), Government of India.

Candidates in the second or higher year of the Four-year Integrated Master's degree programme (Post-B.Sc.) in Engineering/Technology or in the third or higher year of Five-year Integrated Master's degree programme and Dual Degree programme in Engineering/Technology.

Candidates with qualifications obtained through examinations conducted by professional societies recognised by UPSC/AICTE (e.g. AMIE) as equivalent to B.E./B.Tech. Those who have completed Section A or equivalent of such professional courses are also eligible.status.

Many students may not be aware that there are several institutions in this country, offering specialized postgraduate programmes in various disciplines. Attractive scholarship / Assistantship for postgraduate courses in engineering / Technology / Architecture /Pharmacy at Engineering colleges / institutes in the country ,are available to those who qualify through GATE.

Objective

To identify meritorious and motivated candidates for admission to Post Graduate Programmes in Engineering, Technology, Architecture and Pharmacy at the National level. To serve as benchmark for normalisation of the Undergraduate Engineering Education in the country.

Why should we take GATE:

M.Tech degree leads to specialization and furthering of interest in a certain area which may lead to Ph.D
M.Tech degree is best for those wishing to apply for Faculty/Research positions in educational Institutes/R&D centers.

Important Dates:

Availability of GATE forms: October, 1st week
Last Date for filling up forms: November, 1st week
Exam Date: 2nd Sunday of February
Results: March 15st

Examination Details:

The examination is a single paper of 3 hours duration and generally consists of Section A (Objective Type) which is of 75 marks and Section B (Problem Type) which is of 75 marks. Total: 150 marks.
You have to opt for your subject and study as per the syllabus mentioned in the GATE brochure.
The subjects of our interest are Computer Science and Engineering, Electronics & Communication Engineering., Electrical Engineering and Instrumentation Engineering. Other subjects are also available such as Mathematics, Physics, etc.
Results of qualified candidates in GATE will give All India Rank and indicate percentile score. For example, a percentile score of 99 means you are in the top 1% category of the candidates who appeared for GATE.
Candidates who get less than 70 percentile get no score card.
GATE scores are valid for 2 years. You may reappear the GATE exam if you are not satisfied with the earlier score and the new score (if better than the old one) will be used for admission purposes.

What to do after Examination:

After publication of GATE results, students must apply to individual Institutes to get their application forms.
Institutes advertise M.Tech admissions in leading newspapers from 1st April till end July. However some Institutes do not advertise and therefore students have to get the forms themselves.
In the application forms, you have to mention your GATE score alongwith other details.
The concerned Institute may conduct written test and/or interview for the purpose of admission.
General thumb rules: If your GATE score in Computer Science is 96 percentile or more then you can try for IITs, if between 85 - 96 percentile, then apply for top RECs, JADAVPUR, SHIBPUR, ROORKEE, etc. If less than 85, you have to look for appropriate institutes.

Scholarship:

During the pursuit of M.Tech, you are paid a scholarship of Rs. 5000.00 per month by the Government of India. This amount is enough for living expenses including purchase of books, etc. The scholarship is paid for the entire 18 months M.Tech period.

Important:

Encourage 3rd year students to also appear GATE along with Final Year students since:

GATE score is valid for 1 years.
The syllabus as required by GATE is generally over by 5th semester.
You can take a second attempt, if bad result comes.

___________________________________________________________________________________

Structure of GATE

Keep track of ever changing GATE Syllabus. Inform the same to others too.
The GATE examination consists of a single paper of 3 hours duration, which contains 60 questions carrying a maximum of 100 marks. The question paper will consist of only multiple choice objective questions. Each question will have four choices for the answer. Only one choice will be correct. Candidates have to mark the correct choice on an Optical Response Sheet (ORS) by darkening the appropriate bubble against each question. There will be negative marking for wrong answers, as given in question paper pattern.
A candidate can choose any one of the papers listed below.
Paper -Code
Aerospace Engineering -AE
Instrumentation Engineering -IN
Agricultural Engineering -AG
Mathematics -MA
Architecture and Planning- AR
Mechanical Engineering-ME
Civil Engineering- CE
Mining Engineering -MN
Chemical Engineering -CH
Metallurgical Engineering -MT
Computer Science and Information Technology -CS
Physics -PH
Chemistry -CY
Production and Industrial Engineering -PI
Electronics and Communication Engineering - EC
Pharmaceutical Sciences- PY
Electrical Engineering- EE
Textile Engineering and Fibre Science-TF
Geology and Geophysics- GG#
Engineering Sciences -XE*
Life Sciences-XL*

#GG (Geology & Geophysics) paper will consist of two parts: Part A and Part B. Part A will be common to both Geology and Geophysics candidates. Part B will contain two sections: Section 1 (Geology) and Section 2 (Geophysics). Geology candidates will attempt questions in Section 1 only. Geophysics candidates will attempt questions in Section 2 only.
*Papers XE and XL are of general nature and will comprise the following sections:

XE paper sections (Engineering Sciences)		XL paper sections (Life Sciences)
SECTIONS	CODE	SECTIONS	CODE
Engineering Mathematics (Compulsory)	A	Chemistry (Compulsory)	H
Fluid Mechanics	B	Biochemistry	I
Materials Science	C	Biotechnology	J
Solid Mechanics	D	Botany	K
Thermodynamics	E	Microbiology	L
Polymer Science and Engineering	F	Zoology	M
Food Technology	G

A candidate appearing in XE or XL paper will be required to answer three sections. Sections (A) and (H) are compulsory in XE and XL papers, respectively. The candidate can choose any two out of the remaining sections listed against the respective papers.
The choice of the appropriate paper is the responsibility of the candidate. Some guidelines in this respect are suggested below:
• Candidate is expected to appear in one of the papers, listed above appropriate to the discipline of his/her qualifying degree.
• Candidate is, however, free to choose any paper according to his/her admission plan, keeping in mind the eligibility criteria of the institutions in which he/she wishes to seek admission.

--------------------------------------------------------------------------------------------------------------------------------------------------Each paper contains 60 questions carrying 100 marks

Question Papers bearing the codes : AE, AG, AR, CE, CH, CS, CY, EC, EE, IN, MA, ME, MN, MT, PH, PI, PY and TF

Paper Code	Patterns of Question papers	Negative Marks for wrong Answer
AE,AG, AR,CE, CH,CS CY,EC, EE,IN, MA,ME, MN,MT, PH,PI, PY,TF	Q.1 to Q.20 : Will carry one mark each (sub-total 20 marks).	1/3 mark will be deducted for each wrong answer.
	Q.21 to Q.50 : Will carry two marks each (sub-total 60 marks)	2/3 mark will be deducted for each wrong answer.
	Q.51 through Q.56 (3 pairs) will be common data questions. Each question will carry two marks	2/3 mark will be deducted for each wrong answer.
	Question pairs (Q.57, Q.58) and (Q.59, Q.60) will be linked answer questions. The answer to the second question of the last two pairs will depend on the answer to the first question of the pair. If the first question in the linked pair is wrongly answered or is un-attempted, then the answer to the second question in the pair will not be evaluated. Each question will carry two marks	There will be negative marks only for wrong answer to the first question of the linked answer question pair i.e. for Q.57 and Q.59, 2/3 mark will be deducted for each wrong answer. There is no negative marking for Q.58 and Q.60.

Hybrid cars

2010-05-07T08:18:00.001-07:00

Abstract

The production of domestic crude has been declining and the transport system has been increasingly dependent on imported crude oil to meet its needs. There is a growing concern that the world may run out of petroleum based fuel resources. All these make it imperative that the search for alternative fuels is taken in right earnest. With the current fuel sources diminishing, we are looking for alternative ways to power our automobiles.

With this goal in mind, Toyota has been actively developing various new technologies from the perspective of achieving energy security and diversifying energy sources, which is necessitated by the dwindling supply of petroleum resources.

In January 1997, Toyota declared the start of the Toyota Eco Project. As part of this effort, Toyota decided to tackle the international challenge of reducing CO₂ emissions in order to prevent global warming and accelerated the development of a hybrid vehicle with the goal of achieving twice the fuel efficiency of conventional vehicles.

Hybrid electric vehicles (HEVs) combine the internal combustion engine of a conventional vehicle with the battery and electric motor of an electric vehicle, resulting in twice the fuel economy of conventional vehicles.

Index

Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1

Hybrid vehicle - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2

Characteristics of Hybrid Systems

Types of Hybrid Systems - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3

Engine and Motor Operation in each system

Compatibility of Environmental & Power Performance - - - - - - - - - - - - 5

Pursuit of World's highest Fuel Efficiency
Innovative Hybrid Vehicle Driving Experience

Working of THS II - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

System Configuration & Hybrid Transmission
System Operation
Actions of Engine, the Generator and the Motor

High voltage system- Generator and motor - - - - - - - - - - - - - - - - - 10

High-voltage power circuit
Output Enhancement Based on High-Speed Rotation of the Generator
Engine
Specifications of new Hybrid System

Conclusion - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12

Introduction

Toyota's mission has always been to provide clean and safe products. Thus, the company has positioned the environment as one of its most important issues and has been working toward creating a prosperous society and a world that is comfortable to live in.

Toyota has developed and has been marketing Electric Vehicles (EV) that use motors for the driving source; Hybrid Vehicles (HV) that combine an engine and a motor, fusing the advantages of these two power sources; Fuel Cell Hybrid Vehicles (FCHV) that use fuel cells (FC) to generate electricity based on a chemical reaction between hydrogen and the oxygen in the air and that supply this electricity to electric motors to produce driving power.

In March 1997, Toyota announced the completion of a new power train called the Toyota Hybrid System (THS) for use in passenger vehicles. This power train combines a gasoline engine and an electric motor, and because it does not require external charging, as do existing electric vehicles, it works within existing infrastructures such as fueling facilities. This system also achieves nearly twice the fuel efficiency of conventional gasoline engines.

Building on the ecology-focused THS, Toyota has developed the concept of Hybrid Energy Drive. Based on this concept, Toyota has developed a new-generation Toyota hybrid system called THS II, which achieves high levels of compatibility between environmental performance and power by increasing the motor output by 1.5 times, greatly boosting the power supply voltage and achieving significant advances in the control system, aiming for synergy between motor power and engine power.

Hybrid vehicle

Fusion between an internal combustion engine and electric motor--achieving different functions through different power combinations

Automobile hybrid systems combine two motive power sources, such as an internal combustion engine and an electric motor, to take advantage of the benefits provided by these power sources while compensating for each other's shortcomings, resulting in highly efficient driving performance. Although hybrid systems use an electric motor, they do not require external charging, as do electric vehicles.

Characteristics of Hybrid Systems:-

Hybrid systems possess the following four characteristics:

Energy-loss reduction: - The system automatically stops the idling of the engine (idling stop), thus reducing the energy that would normally be wasted.

Energy recovery and reuse: - The energy that would normally be wasted as heat during deceleration and braking is recovered as electrical energy, which is then used to power the starter and the electric motor.

Motor assist: - The electric motor assists the engine during acceleration.

High-efficiency operation control: - The system maximizes the vehicle's overall efficiency by using the electric motor to run the vehicle under operating conditions in which the engine's efficiency is low and by generating electricity under operating conditions in which the engine's efficiency is high.
The series/parallel hybrid system has all of these characteristics and therefore provides both superior fuel efficiency and driving performance.

	Fuel economy improvement				Driving performance
	Idling stop	Energy recovery	High- efficiency operation control	Total efficiency	Acceleration	Continuous high output
Series
Parallel
Series/parallel

Excellent Superior Somewhat unfavorable

Types of Hybrid Systems

The following three major types of hybrid systems are being used in the hybrid vehicles currently on the market:

Series hybrid system

The engine drives a generator, and an electric motor uses this generated electricity to drive the wheels. This is called a series hybrid system because the power flows to the wheels in series, i.e., the engine power and the motor power are in series. A series hybrid system can run a small-output engine in the efficient operating region relatively steadily, generate and supply electricity to the electric motor and efficiently charge the battery. It has two motors—a generator (which has the same structure as an electric motor) and an electric motor. This system is being used in the Coaster Hybrid.

Parallel hybrid system

In a parallel hybrid system, both the engine and the electric motor drive the wheels, and the drive power from these two sources can be utilized according to the prevailing conditions. This is called a parallel hybrid system because the power flows to the wheels in parallel. In this system, the battery is charged by switching the electric motor to act as a generator, and the electricity from the battery is used to drive the wheels. Although it has a simple structure, the parallel hybrid system cannot drive the wheels from the electric motor while simultaneously charging the battery since the system has only one motor.

Series/parallel hybrid system

This system combines the series hybrid system with the parallel hybrid system in order to maximize the benefits of both systems. It has two motors, and depending on the driving conditions, uses only the electric motor or the driving power from both the electric motor and the engine, in order to achieve the highest efficiency level. Furthermore, when necessary, the system drives the wheels while simultaneously generating electricity using a generator.

Engine and Motor Operation in each system

The chart below shows how the ratio of use between engine and motor differs depending on the hybrid system.

Since a series hybrid uses its engine to generate electricity for the motor to drive the wheels, the engine and motor do about the same amount of work.

A parallel hybrid uses the engine as the main power source, with the motor used only to provide assistance during acceleration. Therefore, the engine is used much more than the motor.

In a series/parallel hybrid (THS in the Prius), a power split device divides the power from the engine, so the ratio of power going directly to the wheels and to the generator is continuously variable. Since the motor can run on this electric power as it is generated, the motor is used more than in a parallel system.

Compatibility of Environmental & Power Performance

Automobiles of the future must increase both environmental and safety performance, while significantly increasing the all-important motor vehicle characteristic of being fun to drive. To achieve superior driving performance, which is the basis for driving enjoyment, the conventional approach has been to increase output and torque by increasing engine displacement or using supercharging.

However, this approach decreases fuel efficiency, making it difficult to achieve compatibility of environmental performance and power. In other words, fuel efficiency and power are in a trade-off relationship. By using the Toyota Hybrid System (THS), the Prius was able to escape the inevitability of this relationship in a paradigm shift. The goal of the Hybrid Synergy Drive concept is to achieve compatibility of high levels of both environmental performance and power.

THS, which is a series parallel hybrid, contains a power split device that splits power into two paths. In one path, the power from the gasoline engine is directly transmitted to the vehicle's wheels. In the other path (electrical path), the power from the engine is converted into electricity by a generator to drive an electric motor or to charge the battery.

The newly developed hybrid system, THS II, targets both greater power and improved motor power transmission efficiency, advancing energy management control for the entire vehicle.

As a result, Hybrid Energy Drive has been developed, which markedly increases power performance, improves acceleration performance, and at the same time achieves the highest degree of environmental performance in the world.

Pursuit of World's highest Fuel Efficiency

The new hybrid system THS II is based essentially on THS. In a bid for even higher efficiency, the new system adopts a high-voltage power circuit between the motor and generator, and greatly reduces energy loss during energy transmission to deliver optimal energy efficiency.

THS II significantly increases the use of the electric motor, and under conditions in which the engine experiences poor efficiency, the engine is stopped and the vehicle runs using only power from the electric motor. Under conditions in which engine efficiency is high, THS II operates the engine at optimal fuel efficiency and generates optimum electricity. It also achieves greater energy regeneration during deceleration and braking, thereby increasing the electricity input/output efficiency, in pursuit of the world's highest fuel efficiency.

In terms of environmental performance, THS II aims to meet the ATPZEV (Advanced Technology Partial Zero Emission Vehicle) Regulations in California, U.S.A, which are proposed to go into effect in 2005, the Ultra-Low Emissions Level in Japan, as well as the EURO IV Regulations, scheduled to go into effect in 2004, thus realizing the world's highest level of clean emissions.

Innovative Hybrid Vehicle Driving Experience

THS II boasts by 1.5 times more power from the motor thanks to a higher rpm of the engine, motor, and generator. It adopts a high-voltage power circuit and a higher-performance battery for increased power supply. As a result, the motor power and engine power together provide a more powerful yet smoother running performance.

Working of THS II

Motor power is used for starting the vehicle. For normal operation, the engine and the motor are optimally controlled to increase fuel efficiency. When powerful acceleration is needed, the high-output motor and the engine generate optimum power. This represents further evolution in smooth yet powerful running performance.

System Configuration & Hybrid Transmission

All of the major components of THS II have been developed by Toyota on its own. The high-voltage power circuits, the motor, the generator and the battery have all been designed anew, enabling further evolution of the hybrid system.

The system consists of two kinds of motive power sources, i.e., a high-efficiency gasoline engine that utilizes the Atkinson Cycle, which is a high-expansion ratio cycle, as well as a permanent magnet AC synchronous motor with 1.5 times more output, a generator, high-performance nickel-metal hydride (Ni-MH) battery and a power control unit.

This power control unit contains a high-voltage power circuit for raising the voltage of the power supply system for the motor and the generator to a high voltage of 500 V, in addition to an AC-DC inverter for converting between the AC current from the motor and the generator and the DC current from the hybrid battery.

Other key components include a power split device, which transmits the mechanical motive forces from the engine, the motor and the generator by allocating and combining them. The power control unit precisely controls these components at high speeds to enable them to cooperatively work at high efficiency.

System Operation

(1) Start and low to mid-range speeds

The engine stops when in an inefficient range, such as at start-up and in low to mid-range speeds. The vehicle runs on the motor alone. (A)

(2) Driving under normal conditions

Engine power is divided by the power split device. Some of the power turns the generator, which in turn drives the motor(B).The rest of the power drives the wheels directly (C). Power allocation is controlled to maximize efficiency.

(3) Sudden acceleration

Extra power is supplied from the battery (A), while the engine and high-output motor provide smooth response (B+C) for improved acceleration characteristics.

(4) Deceleration, braking

The high-output motor acts as a high-output generator, driven by the vehicle's wheels. This regenerative braking system recovers kinetic energy as electrical energy, which is stored in the high-performance battery. (D)

(5) Battery recharging

Battery level is managed to maintain sufficient reserves. The engine drives the generator to recharge the battery when necessary. (E)

(6) At rest:- The engine stops automatically.

Actions of Engine, the Generator and the Motor

(1) When the vehicle is at rest

The engine, the generator and the motor are stopped

(2) During start-up

The vehicle starts moving using only the motor drive.

(3) During acceleration from start

The generator, which also has the function of an engine starter, rotates the sun gear and starts the engine. Once the engine has started, the generator begins generating electricity, which is used for charging the battery and supplied to the motor for driving the vehicle

(4) During normal driving

For the most part, the engine is used for driving. Electricity generation is basically not necessary.

(5) During acceleration

During acceleration from the normal driving state, the engine rpm is increased and, at the same time, the generator begins generating electricity. Using this electricity and electricity from the battery, the motor adds its driving power, augmenting the acceleration.

High voltage system- Generator and motor

High-voltage power circuit

The high-voltage power circuit is a new technology that supports the new THS II system. By providing a newly developed high-voltage power circuit inside the power control unit, the voltage of the motor and the generator has been increased from 274V in THS to a maximum of 500V in THS II. As a result, electrical power can be supplied to the motor using a smaller current, thus contributing to an increase in efficiency.

Power (P) = Voltage (V) x Current (I)

Power, which expresses the work performed by electricity within a given amount of time, is calculated by multiplying voltage by current. If the power necessary for driving the motor is held constant, the above formula indicates that doubling the voltage reduces the current by 1/2.

Next, by following Joule's Law (Calorie = Current2 x Resistance), the power loss in terms of calories is reduced to 1/4 (1/2 Current x 1/2 Current) if the resistance is held constant.

The high-voltage power circuit in THS II increases power by increasing the voltage while keeping the current constant. Furthermore, for the same power level, increasing the voltage and reducing the current reduces energy loss, resulting in higher efficiency.

Output Enhancement Based on High-Speed Rotation of the Generator

Because the maximum possible rpm of the generator has been increased, it can draw on higher engine rpm, thereby producing higher output. As a result, the amount of electricity created by the generator is increased, and this increased amount feeds the motor, thus leading to an increase in driving power.

Engine

A 1.5-liter engine is used, which achieves high efficiency by using the Atkinson Cycle, one of the most heat-efficient, high-expansion ratio cycles. Because the expansion ratio is increased by reducing the volume of the combustion chamber and the chamber is evacuated only after the explosion force has sufficiently fallen, this engine can extract all of the explosion energy. Using this type of engine that synergistically works with motor output and achieving high-efficiency operation and comfortable cruising through the synergistic effect of high-torque motor output.

Specifications of new Hybrid System

	Item	THS II	THS
Engine	Type	1.5 L gasoline (high-expansion ratio cycle)
	Maximum output in kw (Ps)/rpm	57 (78)/5,000	53 (72)/4,500
	Maximum torque in N-m (kg m)/rpm	115 (11.7)/4,200	115 (11.7)/4,200
Motor	Type	Synchronous AC motor
	Maximum output in kw (Ps)/rpm	50 (68)/1,200-1,540	33 (45)/1,040-5,600
	Maximum torque in N-m (kg m)/rpm	400(40.8)/0-1,200	350(35.7)/0-400
System*	Maximum output in kW (Ps)/vehicle speed km/h	82(113)/85 or higher	74 (101)/120 or higher
	Output at 85km/h in kW (PS)	82 (113)	65 (88)
	Maximum torque in N-m (kg m)/vehicle speed km/h	478(48.7)/22 or lower	421 (42.9)/11 or lower
	Torque at 22km/h in N-m (kg m)	478 (48.7)	378 (38.5)
Battery	Type	Nickel-metal hydride

*Maximum combined engine and hybrid battery output and torque constantly available within a specified vehicle speed range (Toyota in-house testing)

Conclusion

HEVs are now at the forefront of transportation technology development. Hybrids have the potential to allow continued growth in the automotive sector, while also reducing critical resource consumption, dependence on foreign oil, air pollution, and traffic congestion.

Toyota has positioned hybrid technology as its key technology. Beginning with the development of EVs and through the commercialization of HVs and FCHVs, its continued efforts have now culminated in the development of THS II. Toyota will continue to endeavor to make technical advances in this area.

The hybrid's complexity, and the fact that some of the best storage and conversion systems have yet to be fully developed, is responsible for varied opinions on hybrids' ultimate impact in the marketplace. As with any new technology, there may be obstructions to its ready acceptance by consumers. But time will soon tell.

Electronic Stability Control

2010-05-05T10:20:00.001-07:00

1. INTRODUCTION

The best protection against crashes is to avoid them completely, but sometimes, even good drivers encounter circumstances that are out of their control. Fortunately, a revolutionary active safety technology, Electronic Stability Control (ESC), serves as a vehicle's sixth sense by anticipating crashes before they occur and automatically intervening to prevent them. ESC provides enhanced stability and control in all driving situations, significantly reducing the risk of a crash, especially on... twisting, country roads or highway ramps. ESC helps to prevent rollovers, skids, spins, and can keep your vehicle on the road.

ECS IN ACTION

When avoiding an obstacle, negotiating a sharp curve, or while driving in bad weather, ESC is there to help. ESC is especially useful in protecting you during oversteering, understeering and in potential rollover situations.

ADVANTAGEOUS OR NOT?

With the invention of the Electronic Stability Program ESP®, manufacturers make an important contribution to the improvement of driving safety. The unique system can defuse accident-prone situations by the detection of delayed or inappropriate reactions of the driver and targeted correction of his steering or braking errors – all the way to the limit area, but always within the laws of driving physics.

Based on sensor signals and simulations, the electronics detect dangerous moments before the driver can even respond. Therefore, ESP® can intervene extremely quickly when the situation gets serious. Thus, the system complements the practice oriented safety concept of Manufacturers in an important point: accident avoidance.

2. HOW ESC WORKS

Electronic Stability Control (ESC) is a stability enhancement system designed to electronically detect and assist the driver in critical driving situations. ESC compares a driver's intended course with the vehicle's actual movement. When instability is detected, ESC automatically applies brakes to individual wheels and can also reduce engine torque to help keep you on track.

ESC is your safety co-pilot, especially during cornering and avoidance maneuvers. The best part is that the system works automatically, so you can concentrate on driving. The ESC system relies on information from:

Wheel speed sensors

Steering wheel angle sensor

Yaw rate and lateral acceleration sensors

Master cylinder pressure sensor

Antilock Braking System (ABS) – Controls break pressure to help prevent wheel lock-up during braking, so you can steer and maneuver around obstacles during braking.

Traction Control System (TCS) – Applies brakes at drive wheels and reduces engine torque to help reduce wheel spin during acceleration. It works across a full range of speeds, whether you're accelerating after a stop or passing on the highway.

Electronic Stability Control (ESC) – Applies brakes to individual wheels and reduces engine torque to help correct oversteer and understeer. It helps you maintain control in all weather conditions, helping to prevent skids, spins and rollovers.

UNDERSTEER

It's late at night and you are on your way back from a weekend trip. You decide to take a new route home. Unfamiliar with the off-ramp, you miscalculate the sharpness of the curve and the front of your vehicle begins to slide to the outside of the turn – a situation known as understeer. ESC begins to work in a split-second.

As the vehicle begins the turn in an understeering situation, the front-end of the vehicle slides out of the lane and out of the driver's control as the wheels lose traction.

ESC automatically applies the inside rear brake to help you achieve your desired turn. Depending on vehicle speed, the system may also reduce engine torque.

OVERSTEER

On an apple-picking outing, you and your family explore the scenic back roads of the country. The rain holds off until you are ready to leave. Everyone piles into the vehicle and you begin to navigate your way back home. During the trip, you encounter an unexpected sharp turn. You jerk the wheel, and the rear-end of the vehicle begins to slip or "fishtail" – a situation known as oversteer. Luckily, ESC is there to help you stay on track.

As the vehicle begins to oversteer, the rear wheels lose traction and you could start to spin out of control.

However, ESC automatically applies the outside front brake to correct the problem and help to prevent a dangerous situation before it happens.

ROLLOVER

You are driving at dusk, the road is wet, you have poor visibility and an animal suddenly runs out in front of you. You slam on the brakes and quickly swerve left then right to avoid it.

In similar circumstances, some vehicles may become unstable and enter into a "tripped rollover" by leaving the road. However, your ESC equipped vehicle stays on the road, keeping you and your family safe.

ESC also helps to prevent vehicles from going sideways or skidding, another condition that contributes to an "on-road rollover."

3.INCURSION

In principle, this event involves the driver performing a double lane change to avoid an obstacle while driving at a high rate of speed. Specifically, the event is designed around a hidden drive way out of which another vehicle backs out in to the path of the driver. The event timing was design to ensure that steering is necessary to avoid colliding with the incurring vehicle. At the same time, on coming traffic was used as a motivator to the second part of the double lane change manure.

To ensure that driver do not slow down in anticipation of a critical event they encounter a similar situation before reaching the actual event nothing of interest takes place when passing a similar house containing various stationary vehicles arranged in a similar configuration .

The posted limit is 65 mph and the road profile used for this scenario is identical to the profile used in the curve departure scenario.

4. TECHNICAL OVERVIEW

The idea behind Electronic Stability Control is simple. It is an active safety system that helps you prevent skidding that can occur in all kinds of weather and on all kinds of roads; in situations where even the best of drivers might struggle to keep their vehicles on the road.

Sensing Safety The system has sensors that compare a vehicle's behavior in relation to steering wheel position. When ESC detects a discrepancy between a driver's intended path and the vehicle's actual path, it intervenes to help bring the movement of the vehicle back in line with your intentions.

Stability The stabilizing effect is based on calculations performed by a microcomputer that evaluates signals from the ESC sensors. The steering-angle sensor registers the steering-wheel position, and wheel speed sensors mounted at each wheel provide the wheel speeds. The data from these sensors enables the system's microcomputer to recognize what maneuvers you intend to perform.

The Heart of the Matter The yaw rate sensor is at the heart of the ESC system. It registers the vehicle's rotation around its vertical axis. A highly sensitive lateral-acceleration sensor reacts to the centrifugal forces that are generated when cornering.

Step 1 The sensors provide a microcomputer known as the Electronic Control Unit (ECU) with information it needs to evaluate the vehicle's behavior at a given instant.

Step 2 The microcomputer uses this information to continuously compare the vehicles actual and the desired movement, and intervenes immediately if the vehicle shows a tendency to leave the intended path of travel.

Step 3 Using programmed set points, which are precisely tailored to the particular vehicle and specific logic operations, the microcomputer, calculates the steps which need to be taken within a fraction of a second.

Step 4 ESC then transmits the appropriate commands to the braking system, which applies a precisely defined brake pressure at appropriate wheels.

Step 5 ESC can also reduce the engine torque when understeering or if wheel spin is detected during acceleration.

5. DEFINATIONS

Electronic Stability Control is a closed-loop stability-control system that relies on proven ABS (Antilock Brake System) and TCS (Traction Control System) components. It incorporates sensors for determining vehicle parameters as well as an ECU (Electronic Control Unit) to modulate braking and traction forces.

Sensors – ESC utilizes the following sensors to deliver the safest driving experience possible:

Wheel speed sensors

Steering wheel angle sensors

Yaw rate and lateral acceleration sensors

Master cylinder pressure sensor

Steering Wheel Angle Sensor – measures the steering wheel angle and steering input rate.

Wheel Speed Sensors – deliver electric pulses from which the ECU (Electronic Control Unit) computes the speed of the wheels. The vehicle speed is derived from the rotational speeds of all wheels by means of a special computational algorithm.

Yaws Rate Sensor – is a gyroscopic sensor that monitors the vehicle's rotation around its vertical axis.

Lateral Acceleration Sensor – measures the acceleration of the vehicle in the direction of the vehicle's lateral axis (side to side motion).

Electronic Control Unit (ECU) – the microcomputer that processes and interprets information from each sensor and then generates the necessary activation commands to control brake pressure and engine torque.

Wheel-speed sensors

The electronic control unit (ECU) uses the signals from the individual wheel-speed sensors to compare the speeds of the wheels. Two different operating principles are used: passive (inductive) and active (Hall) speed sensors. Active sensors can also recognize the direction of wheel rotation.

Hydraulic modulator with attached ECU

Through commands from the ECU, the hydraulic modulator regulates the pressure in the individual brake cylinders by means of solenoid valves. The hydraulic unit is located in the brake system between the master cylinder and the brake cylinders. The ECU controls all electrical and electronic tasks as well as controls the functions of the system.

Steering-wheel angle sensor

The combination of signals from the wheel-speed sensors and steering-wheel angle sensor provides the input for ESC to interpret the intended course of the vehicle. The steering-wheel angle sensor has a working range of 720° with a tolerance of ± 5°.

ESC communicates with engine management systems

Involved engine management system components include:

- Engine ECU

- Accelerator-pedal sensor

- Throttle-valve actuator

- Fuel injectors

- Ignition module

Yaw-rate and acceleration sensor

A yaw-rate sensor detects the vehicle's rotational movements around its vertical axis.

The principle for measuring rate of yaw is based on how forces (known as Coriolis forces) act on a mass moving forward in a rotating system (this movement is termed "translation"). If there are oscillating mass elements in this system, this oscillatory action is affected once the system starts to rotate. The manipulated variable needed to return the oscillatory motion produces a voltage which is translated into a measurement of the yaw rate.

6. PRINCIPLE OF ESP OPERATION

7. SAFETY

Mercedes Passenger Cars Get Into Fewer Accidents

‧Accident rate dropped by 15 percent especially due to standard ESP

‧Share in driving accidents with serious consequences declining greatly since 2000

‧Stability program makes important contribution to accident prevention

The number of Mercedes passenger cars with road traffic accidents has declined sharply since the series production/standard employment of the Electronic Stability Program ESP.

This is shown by a representative random sample analysis of the accident data* of the Federal Statistics Office, which Mercedes-Benz published today. Accordingly, the accident rate of Mercedes Models first licensed in 2000/2001 compared with 1999/2000 has dropped by 15 percent, and thus dropped by 4 percentage points more than the average of other automobile manufacturers. Mercedes-Benz analyzed a total of over 1.5 million traffic accidents. As the first automobile brand, Mercedes-Benz put the Electronic Stability Program ESP into all of it's passenger car models, starting in the summer of 1999, as standard equipment, which reduces the danger of spinning in curves, in avoidance maneuvers or during braking, and supports the driver in better controlling critical situations. "The current analysis of the accident statistics shows, that ESP makes an important contribution to accident prevention, and is therefore as significant for traffic safety as ABS, seat belt and airbag," says Dr. Hans-Joachim Schöpf, head of passenger car development at Mercedes-Benz.

Reduction of Casualty rate by Extent of Injury for Toyota in Japan

Toyota has named its program as Vehicle Stability Control

8. HOW EFFECTIVE IS IT?

The results are extraordinary, in that the effectiveness of ESP is large and consistent, and just on an isolated accident type or event it is therefore essential, that the method and the possible bias are challenged. There are a few possible explanations to the results, given that ESP was effective in reducing the accidents. Firstly, if rear end impacts was an accident type, where ESP drivers showed their aggressiveness and risk compensation more, than in all other accident types, the results could show the same profile as in this study. The fact that both ESP cars and non-ESP cars show the same profile in being target and bullet vehicles in rear is an indication of that this assumption does not show in reality. Secondly, same results could be present if ESP cars were exposed to driving on low friction surface. Such factor is very complicated to analyze with induced exposure. It is, given the way the data was assembled, not a plausible explanation. Still, the study should be repeated also in Sweden, also to study the long term effects of ESP. In the meantime, the likely explanation to the results that ESP in fact is effective. The method used in the present study, does not allow an analysis on the actual function of the system, and in what sequence of driving it has its potential.

Wheather ESP works as an intelligent system to warn the driver about low friction, or if it has a direct function in the driver-vehicle loop in critical manoeuvres, either in controlling stability and/or reduce speed, was not possible to study. It was not possible to study to what extent the effectiveness varied over accident types or events. Further studies should try to analyze this in-depth. It should also be analyzed, if the severity of impacts is reduced by ESP. A recent development of ESP that would most probably increase the effectiveness is the link between the ESP being active and the passive safety system of the car being alerted and start to act. In Mercedes-Benz S-Class update 2002, both the ESP and the brake assist system will trigger a reversible seat belt pretension, to bring the occupant in a favorable position before a possible crash. Also other functions of the vehicle are also triggered. In this sense, the ESP is used as a device for increasing the crash protection of the car. The effectiveness of ESP is promising enough, to stimulate automotive industry and consumers to implement ESP in new cars as quickly as possible. Therefore, consumers should be advised to choose cars with ESP, especially in countries with wet and icy road conditions. While the effectiveness on dry roads was not significant, accidents on both wet as well as roads covered with snow or ice were significantly reduced.

9. CONCLUSION

- ESC is found to reduce accidents with personal injuries.

- The effectiveness on all accidents, except rear-end impacts on dry road surface, was 1.1% to 43.1%, with best estimate 22.1%

- The effectiveness on roads with lower friction was substantially higher, 7.8-55.2% and 12.1-64.3% (best estimates 31.8 and 38.2%), for wet roads and roads covered with ice or snow, respectively.

- The results broken down to vehicle types were consistent with the above results, in some cases though not statistically significant.

A new database, EACS (the European Accident Causation Survey) was used for the first time to estimate the potential opportunity for an active safety system based on the number of accidents in which it is judged that the presence of the system would have influenced the outcome. The EACS data suggest that ESC could have a probable or definite influence in about 67% of fatal accidents involving loss of vehicle control and 42% of the corresponding injury accidents. However, some cautions about potential effectiveness estimates produced in this way have been raised. In particular, data consistency between teams in different countries and lack of national or international representivity in the EACS sample were identified as particular concerns.

MECHANICAL BASE

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ABSTRACT

INTRODUCTION

THE DESIGN CONCEPT

TEST SETUP

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TESTING

RESULTS

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“NETWORK SECURITY”

INTRODUCTION

Network

SECURED COMMUNICATION

SECRECY

AUTHENTICATION

MESSAGE INTEGRITY

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CONCLUSION

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Electronic Stability Control