Skid Steer Loader and Multiterrain Loader(mechanical seminar topics)

Definition

Skid-steer loaders began catching on in the construction field in the 1980s because they offered contractors a way to automate functions that had previously been performed by manual labor.

Those were small, inexpensive machines that improved labor productivity and reduced work-related injuries. Their small size and maneuverability allows them to operate in tight spaces. Their light weight allows them to be towed behind a full-size pickup truck, and the wide array of work-tools makes them very flexible. They were utility machines, used for odd jobs ranging from work site clean up to small scale digging, lifting, and loading. In most cases, they logged far fewer hours of usage each year than backhoe loaders and wheel loaders, but they were cheap, and so easy to operate that anyone on a job site could deploy them with very little training.

Since then, the category has become wildly popular in all avenues of construction. They are the best-selling type of construction equipment in North America, with annual sales exceeding 50,000 units. They still tend to be low-hour machines, but, thanks to a virtually unlimited variety of attachments, skid-steer loaders can handle a huge array of small-scale jobs, from general earthmoving and material handling to post hole digging and landscaping to pavement milling and demolition.

As the machine has grown in popularity, it has become one of the hottest rental items in North America. Equipment rental houses consume roughly one-third of the new units sold each year, and most stock a wide array of attachments, too. The ready availability of rental attachments - especially high-ticket, specialty items like planers, vibratory rollers, tillers, and snow blowers and pushers - has turned the machines potential for versatility into a cost-effective reality.

As the skid-steer has become more popular in construction, the average size of the machine has grown, too. In the mid-1980s, the most popular operating load class was 900 to 1,350 pounds. By the mid-1990s, the 1,350 to 1,750 pound class was the most popular. Today, the over-1,750-pound classifications are the fastest growing.

Larger machines have dominated new product introductions, too, though our survey of recent new product announcements has turned up a spate of compact and sub-compact introductions, too. The smallest of these are ride-behind models aimed mainly at the consumer rental trade, but they are also used in landscaping and other types of light construction essentially to automate jobs that would otherwise be done by laborers with shovels.

Road contractors and government highway departments should find the new super-duty class of skid-steer loaders especially interesting. These units have retained the skid-steer's traditional simplicity of operation and compact packaging, while also boasting power and weight specifications that let them perform many of the tasks done by backhoe loaders and compact wheel loaders. Nearly all boast high-pressure, high-flow hydraulic systems to run the most sophisticated hydraulic attachments. They also feature substantial break-out force ratings for serious loading and substantial lifting capacities for material handling.

The skid-steer loader represents an interesting alternative for fleets that have low- hour backhoe loaders in inventory. Led by Bobcat, Gehl, Mustang, and other companies that make skid-steers but not backhoe loaders, skid-steer marketers have been pushing the proposition that it is more cost effective to replace a backhoe loader with a skid-steer and a mini-excavator. The rationale: for about the same amount of money, you can get more hours of utilization because you have two machines that can be working simultaneously at different jobs.

F1 Track Design and Safety

Definition

Success is all about being in the right place at the right time ….. and the axiom is a guiding principle for designers of motorsport circuits. To avoid problems you need know where and when things are likely to go wrong before cars turn a wheel -and anticipating accidents is a science.

Take barriers, for example .there is little point erecting them in the wrong place -but predicting the right place is a black art. The FIA has developed bespoke software, the Circuit and Safety Analysis System (CSAS), to predict problemareas on F1 circuits.

Where and when cars leave circuits is due to the complex interaction between their design, the driver's reaction and the specific configuration of the track, and the CSAS allows the input of many variables-lap speeds ,engine power curves, car weight changes, aerodynamic characteristics etc -to predict how cars may leave the circuit at particular places. The variables are complex. The impact point of a car continuing in a straight line at a corner is easy to predict, but if the driver has any remaining control and alters the car's trajectory, or if a mechanical fault introduces fresh variables, its final destination is tricky to model.

Modern tyre barriers are built of road tyres with plastic tubes sandwiched between them. The side facing the track is covered with conveyor belting to prevent wheels becoming snagged and distorting the barrier. The whole provides a deformable 'cushion' a principle that has found its way to civilian roads. Barriers made of air filled cells, currently under investigation may be the final answer. Another important safety factor is the road surface. Racing circuits are at the cutting edge of surface technology, experimenting with new materials for optimum performance.

Circuit and Safety Analysis System (CSAS)

Predicting the trajectory and velocity of a racing car when it is driven at the limit within the confines of a racing track, is now the subject of a great deal of analytical work by almost all teams involved in racing at all levels. However, predicting the trajectory and velocity of a car once the driver has lost control of it has not been something the teams have devoted a great deal of time to. This can now also be analyzed though in the same sort of detail, to assess the safety features of the circuits on which it is raced. The two tasks are very different, and the FIA had to start almost from scratch when it set out to develop software for its Circuit and Safety Analysis System (CSAS).

The last two decades have seen a steady build up of the R&D effort going into vehicle dynamics modeling, particularly by those teams that design and develop cars as well as race them. The pace of development has been set by the availability of powerful PC's, the generation of vehicle and component data, and the supply of suitably qualified graduates to carry out the work. Their task is to be able to model and predict the effects of every nuance of aerodynamic, tire, engine, damper etc., characteristic on the speed of their car at every point on a given circuit. The detail in the model will only be limited by available dynamic characteristics and track data, and will require a driver model to complete the picture. However, they are only interested in the performance of the car while the tires are in contact with the tarmac, and the driver is operating them at or below their peaks.

Green Engine(mechanical seminar topics)

Definition

Global Issues

Everyday radios, newspapers, televisions and the internet warn us of energy exhaustion, atmospheric pollution and hostile climatic conditions. After few hundred years of industrial development, we are facing these global problems while at the same time we maintain a high standard of living. The most important problem we are faced with is whether we should continue "developing" or "die".

Coal, petroleum, natural gas, water and nuclear energy are the five main energy sources that have played important roles and have been widely used by human beings.

The United Nations Energy Organization names all of them "elementary energies", as well as "conventional energies". Electricity is merely a "second energy" derived from these sources. At present, the energy consumed all over the world almost completely relies on the supply of the five main energy sources. The consumption of petroleum constitutes approximately 60 percent of energy used from all sources, so it is the major consumer of energy.

Statistics show that, the daily consumption of petroleum all over the world today is 40 million barrels, of which about 50 percent is for automobile use. That is to say, auto petroleum constitutes about 35 percent of the whole petroleum consumption. In accordance with this calculation, daily consumption of petroleum by automobiles all over the world is over two million tonnes. At the same time as these fuels are burnt, poisonous materials such as 500 million tonnes of carbon monoxides (CO), 100 million tonnes of hydrocarbons (HC), 550 million tonnes of carbon (C), 50 million tonnes of nitrogen oxides (NOx) are emitted into the atmosphere every year, severely polluting the atmosphere. At the same time large quantities of carbon dioxide (CO2) gases, resulting from burning, have also taken the major responsibility for the "green house effect".

Atmospheric scientists now believe that carbon dioxide is responsible for about half the total "green house effect". Therefore, automobiles have to be deemed as the major energy consumer and atmosphere's contaminator. Also, this situation is fast growing with more than 50 million vehicles to be produced annually all over the world and place into the market. However, at is estimate that petroleum reserve in the globe will last for only 38 years . The situation is really very grim.

Addressing such problems is what a Green engine does or tries to do. The Green engine as it is named for the time being, is a six phase engine, which has a very low exhaust emission, higher efficiency, low vibrations etc. Apart from these features, is its uniqueness to adapt to any fuel which is also well burnt. Needless to say, if implemented will serve the purpose to a large extent.

Compared to conventional piston engines, operated on four phases, the Green engine is an actual six phase internal combustion engine with much higher expansion ratio. Thus it has six independent or separate working processes: intake, compression, mixing, combustion, power and exhaust, resulting in the high air charge rate. Satisfactory air-fuel mixing, complete burning, high combustion efficiency and full expansion. The most important characteristic is the expansion ratio being much bigger than the compression ratio.

IP spoofing(mechanical seminar topics)

Definition

Criminals have long employed the tactic of masking their true identity, from disguises to aliases to caller-id blocking. It should come as no surprise then, that criminals who conduct their nefarious activities on networks and computers should employ such techniques. IP spoofing is one of the most common forms of on-line camouflage. In IP spoofing, an attacker gains unauthorized access to a computer or a network by making it appear that a malicious message has come from a trusted machine by "spoofing" the IP address of that machine. In the subsequent pages of this report, we will examine the concepts of IP spoofing: why it is possible, how it works, what it is used for and how to defend against it.

Brief History of IP Spoofing

The concept of IP spoofing was initially discussed in academic circles in the 1980's. In the April 1989 article entitled: "Security Problems in the TCP/IP Protocol Suite", author S. M Bellovin of AT & T Bell labs was among the first to identify IP spoofing as a real risk to computer networks. Bellovin describes how Robert Morris, creator of the now infamous Internet Worm, figured out how TCP created sequence numbers and forged a TCP packet sequence. This TCP packet included the destination address of his "victim" and using an IP spoofing attack Morris was able to obtain root access to his targeted system without a User ID or password. Another infamous attack, Kevin Mitnick's Christmas Day crack of Tsutomu Shimomura's machine, employed the IP spoofing and TCP sequence prediction techniques. While the popularity of such cracks has decreased due to the demise of the services they exploited, spoofing can still be used and needs to be addressed by all security administrators. A common misconception is that "IP spoofing" can be used to hide your IP address while surfing the Internet, chatting on-line, sending e-mail, and so forth. This is generally not true. Forging the source IP address causes the responses to be misdirected, meaning you cannot create a normal network connection. However, IP spoofing is an integral part of many network attacks that do not need to see responses (blind spoofing).

2. TCP/IP PROTOCOL Suite

IP Spoofing exploits the flaws in TCP/IP protocol suite. In order to completely understand how these attacks can take place, one must examine the structure of the TCP/IP protocol suite. A basic understanding of these headers and network exchanges is crucial to the process.

2.1 Internet Protocol - IP

The Internet Protocol (or IP as it generally known), is the network layer of the Internet. IP provides a connection-less service. The job of IP is to route and send a packet to the packet's destination. IP provides no guarantee whatsoever, for the packets it tries to deliver. The IP packets are usually termed datagrams. The datagrams go through a series of routers before they reach the destination. At each node that the datagram passes through, the node determines the next hop for the datagram and routes it to the next hop. Since the network is dynamic, it is possible that two datagrams from the same source take different paths to make it to the destination. Since the network has variable delays, it is not guaranteed that the datagrams will be received in sequence. IP only tries for a best-effort delivery. It does not take care of lost packets; this is left to the higher layer protocols. There is no state maintained between two datagrams; in other words, IP is connection-less.

Lean manufacturing(mechanical seminar topics)

INTRODUCTION

In 1900's U.S. manufacturers like Henry ford brought the concept of mass production. U.S. manufacturers have always searched for efficiency strategies that help reduce costs, improve output, establish competitive position, and increase market share. Early process oriented mass production manufacturing methods common before World War II shifted afterwards to the results-oriented, output-focused, production systems that control most of today's manufacturing businesses.

Japanese manufacturers re-building after the Second World War were facing declining human, material, and financial resources. The problems they faced in manufacturing were vastly different from their Western counterparts. These circumstances led to the development of new, lower cost, manufacturing practices. Early Japanese leaders such as the Toyota Motor Company's Eiji Toyoda, Taiichi Ohno, and Shingeo Shingo developed a disciplined, process-focused production system now known as the "lean production." The objective of this system was to minimize the consumption of resources that added no value to a product.

The "lean manufacturing" concept was popularized in American factories in large part by the Massachusetts Institute of Technology study of the movement from mass production toward production as described in The Machine That Changed the World, (Womack, Jones & Roos, 1990), which discussed the significant performance gap between Western and Japanese automotive industries. This book described the important elements accounting for superior performance as lean production. The term "lean" was used because Japanese business methods used less human effort, capital investment, floor space, materials, and time in all aspects of operations. The resulting competition among U.S. and Japanese automakers over the last 25 years has lead to the adoption of these principles within all U.S. manufacturing businesses. Now it has got global acceptance and is adopted by industries world over to keep up with the fast moving and competing industrial field.

WHAT IS LEAN MANUFACTURING?
Lean manufacturing is a manufacturing system and philosophy that was originally developed by Toyota, Japan and is now used by many manufacturers throughout the world.

Lean Manufacturing can be defined as:
"A systematic approach to identifying and eliminating waste (non-value-added activities) through continuous improvement by flowing the product at the pull of the customer in pursuit of perfection."

The term lean manufacturing is a more generic term and refers to the general principles and further developments of becoming lean.The term lean is very apt because in lean manufacturing the emphasis is on cutting out "FAT" or wastes in manufacturing process. Waste is defined as anything that does not add any value to the product. It could be defined as anything the customer is not willing to pay for.

Manufacturing philosophy is pivoted on designing a manufacturing system that perfectly blends together the fundamentals of minimizing costs and maximizing profit. These fundamentals are Man (labour), Materials and Machines (equipments) called the 3 M's of manufacturing. A well-balanced 3M is resulted through lean manufacturing.

WASTES IN MANUFACTURING
The aim of Lean Manufacturing is the elimination of waste in every area of production including customer relations, product design, supplier networks, and factory management. Its goal is to incorporate less human effort, less inventory, less time to develop products, and less space to become highly responsive to customer demand while producing top quality products in the most efficient and economical manner possible.

Essentially, a "waste" is anything that the customer is not willing to pay for.
Typically the types of waste considered in a lean manufacturing system include:

Overproduction
To produce more than demanded or produce it before it is needed. It is visible as storage of material. It is the result of producing to speculative demand. Overproduction means making more than is required by the next process, making earlier than is required by the next process, or making faster than is required by the next process.
Causes for overproduction waste include:
" Just-in-case logic
" Misuse of automation
" Long process setup
" Unleveled scheduling
" Unbalanced work load
" Over engineered
" Redundant inspections

Electro Discharge Machining(mechanical seminar topic)

The unconventional method of several specific advantages over conventional methods of machining and these promise formidable tasks to be undertaken and set a new recording in the manufacturing technology. EDM is one such machiningThe unconventional method of several specific advantages over conventional methods of machining and these promise formidable tasks to be undertaken and set a new recording in the manufacturing technology. EDM is one such machining process, which has been immense help to the manufacturing process engineers to produce intricate shapes on any conducting metal and alloy irrespective of its hardness and toughness.

CLASSIFICATION

1. Contact initiated discharge 2. Spark initiated discharge 3. Electrolytic discharge ADVANTAGES

1. The process can be applied to all electrically conducting metal and alloyes irrespectives of their melting points, hardness, toughness, or brittleness 2. Any complicated shape that can be made on the tool can be produced on the work piece 3. Time of machining is less than conventional machining process DISADVANTAGES

1. Power required for machining in E.D.M is very high compared to conventional process. 2. Reproduction of sharp corners is the limitation of the process. 3. Surface cracking takesplace in some materials. process, which has been immense help to the manufacturing process engineers to produce intricate shapes on any conducting metal and alloy irrespective of its hardness and toughness.

CLASSIFICATION

1. Contact initiated discharge 2. Spark initiated discharge 3. Electrolytic discharge ADVANTAGES

1. The process can be applied to all electrically conducting metal and alloyes irrespectives of their melting points, hardness, toughness, or brittleness 2. Any complicated shape that can be made on the tool can be produced on the work piece 3. Time of machining is less than conventional machining process DISADVANTAGES

1. Power required for machining in E.D.M is very high compared to conventional process. 2. Reproduction of sharp corners is the limitation of the process. 3. Surface cracking takesplace in some materials.