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Archive for March 31st, 2011

style=”text-align:justify;”>Electric Cars use electricity instead of gasoline to propel the vehicle.

By doing so they save on gasoline, and provide an option for countering the impact of rising gas prices. In addition, they also cut down on the dangerous emission of green house gases that pose a great threat to environmental integrity today.

Using Electricity to run the Car

Instead of the internal combustion engine that runs the conventional gasoline car, the electric car uses electricity and has a three component system instead of engine.

Electric Motor- The car is moved by the electric motor that moves its wheels.  Essentially it performs the function of a conventional gas engine.
Controller – It serves to pass on the power to the motor from the batteries.
Rechargeable Batteries- They serve to store energy that is used to drive the vehicle. Charging of batteries can be done from a power grid, at home or in designated recharging site. Their size and efficiency is the biggest limiting factor, and their disposal one of the biggest challenges currently faced.

Pure Electric Vs. Hybrid Vs. Fuel Cell Cars

Currently used electric cars can be classified in three major groups.

1. Pure Electric Cars : These are vehicles that depend solely on electricity stored in batteries for moving the cars. They do not have any gasoline engine, and recharging of car is done through power grid. Example include REVA electric vehicle, which is one of the earliest models to have gained popularity.

2. Hybrid Cars : These are vehicles with electric batteries as well as a conventional gasoline internal combustion engine, with a complex computerized control to automatically shift the power from batteries to engine and vice versa depending upon needs.

3. Fuel Cell Cars : These are also electric vehicles as they use electricity to propel the car. However, instead of storage in rechargeable batteries, electricity is generated in the fuel cells by utilizing hydrogen to produce electricity and water.

Features of Electric Cars

Technological advancements have now placed electric cars at par with conventional cars in terms of speed etc. Tesla Roadster, one of the latest models launched this year can accelerate from 0 to 210 km in 4 seconds and has a fuel efficiency of 1.74 L/100 km, which is equivalent to 135 miles per U.S. gallon.

These newer models have largely taken care of the slow speed associated with electric vehicles.

Apart from speed, other constraints of electric vehicles are battery storage, environmental concerns of battery disposal and losses of energy in various stages of production and distribution of power and its actual use in the car.

The electric vehicles provide a greater efficiency of energy used. Simultaneously, they also reduce the emissions. Thus they provide an environmentally friendly solution to the challenge of carbon emissions and depleting oil.

Role of Electrical Cars

So far the use of electric cars has been more or less experimental in nature. With improving technology, falling battery costs and rising gas prices, they are likely to become a major option that can be considered for replacing gas engine cars.

Hybrid cars, fuel cell cars and electric cars are likely to become more popular due to fuel cost savings as well as incentives attached in the form of tax breaks, and other forms of government policy encouragement.

One of the greatest advantages of electric vehicles is that they provide a way to run cars on electricity that can be generated from renewable sources. This way they could provide a solution to depleting oil, rising oil prices and threatening carbon emissions.

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by Wesley Fryer

What is Distance Learning?

The first distance learning can be traced back to the 18th Century, in the form of ‘correspondence courses’, which became increasingly popular with the development of the postal system throughout the 19th century.

Distance learning was born out of the difficulty many people had in accessing education – either due to ill health, inability to travel, financial problems, working or family commitments or being unable to attend institutions due to restrictions on the admission of women.

Since then, education has probably become more easily accessible than ever before. However, distance learning still serves a useful purpose as a means for those who are unable to attend physical classes to study and gain qualifications. Its flexibility and convenience has meant that distance learning has gone from strength to strength over its 250 year history, and it is more popular now than ever before.

Synchronous or Asynchronous?

Distance learning courses can be ‘synchronous’ or ‘asynchronous’.

Synchronous learning means that you study as part of a class of students at a set time each week, for example if you and other pupils attend virtual ‘classes ‘ or seminars with your tutor via conference calls, video chats or over the internet. Synchronous distance learning courses are good for students who are able to set aside a period of time every week – these types of courses are the closest to attending a traditional class-based course at a college.

Asynchronous learning means that you complete your studies in your own time, and communicate with your tutor via email, message boards or telephone when you need advice or assistance. This method of study is best for people with busy or unpredictable schedules, as they can fit in their learning around their other commitments. However, it does require a little more discipline than a synchronous learning course to keep on track with your work.

Distance Learning

Modern distance learning still has a lot in common with the original correspondence courses – when you enrol on a course you’ll be sent the books and other materials you need to complete the course and will be assigned a tutor. Your tutor will set you assignments to complete, and you’ll return work to them for marking as well as contacting them by telephone or email if you need help.

Self Study

Self study is a minimalist form of distance learning – when you enrol on a self-study course, you’ll receive your course materials, vouchers for your exams and not much more. You may be assigned a tutor, but it’s likely that contact with them will be limited, or you might not receive any further help at all. Self-study courses are generally much cheaper than other forms of distance learning, as they don’t cost as much to deliver as courses where more tutor support is available. Self study courses work best if you’re very confident with your subject matter, or if you’re extremely self-motivated. However, if you’re less confident with learning alone you may want to consider a course that offers more support.

E-Learning

E-Learning, as the name suggests, is conducted mostly or completely online. For an E-learning course, instead of receiving materials through the post you’ll log into an online system where you can read study guides, complete activities and submit work. Because the cost of materials is reduced, E-learning can be good value for money, and many people find being able to log into the system from any computer to be a convenient way to work. However, E-learning isn’t necessarily for everybody – if you’re not confident with computers or if you don’t have a fast, reliable internet connection you might find working with hard copy textbooks more productive.

Blended Learning

Blended learning is a combination of distance learning and traditional classroom teaching. On a blended learning course, you’ll study most of the course via distance learning using one of the methods above. In addition, you’ll also have one or more in-person classroom sessions with your tutor. This system of learning is common in business training, when a number of people from the same company are studying the same course. Blended learning gives the best of both worlds, adding a social aspect to distance learning and helping students to stay motivated on their course while still offering flexibility.

Summary

Understanding the difference between different types of distance learning is important when choosing the right course for you – by finding out exactly what each course offers, you can choose the one that best suits your learning style and personal circumstances. Good luck!

Why Electric Mowers?

People who choose electric do so for a variety of reasons. Some want to go electric for environmental reasons. As we become a more eco-friendly society, many of our buying decisions are determined by whether the product is good for our planet. An electric lawn mower certainly falls into that category. It emits zero emission and does not contribute to pollution, unlike its gas counterpart.

Another reason people like electric mowers is because it’s much quieter to operate than gas mowers. Gas engines are noisy, so if you go electric, you won’t disturb your neighbors when mowing early in the morning. Also, you won’t need to wear ear protection to block out the sound made by the loud gas engine.

Easy to Maintain

Over and over again, you’ll hear people who use electric lawn mowers say how easy it is to maintain. Unlike those that are powered by gas, you do not have to deal with gasoline, changing the oil and filters, or issues with spark plugs. The only maintenance that’s really required is making sure the blade is sharp and keeping the undercarriage clear of debris.

Downsides to Buying Electric Mowers

While electric lawn mowers have come a long way in the past decade, it still lags behind gas mowers in terms of power. If you have a regular-sized lawn and the turf is relatively level, then an electric mower should perform just as well as a gas mower under those conditions. However, if you have large, hilly lawns, you’d be better off buying a gas mower.

Another downside to electric mowers is the use of cords in the corded models. For some it’s a minor inconvenience, for others, trying to wrangle a cord while mowing can really test your patience. It is not uncommon for people to accidentally run over their power cord while mowing. You can avoid this hassle by buying the cordless models. With the cordless models, the mower is powered by a battery. While it’s convenient, keep in mind that the battery usually adds a lot of weight to the mower. So, if you don’t want to push a heavy mower around, consider your other options.

Also, if you buy a cordless model, consider whether you can mow your entire lawn on one charge. If not, consider buying a model that has the removable battery feature and get a back-up battery. Otherwise, if you run out of battery before finishing, you’ll have to stop and wait several hours to recharge the battery.

Reasons to Buy a Gas-Powered Mower

With a powerful gas engine, a gas lawn mower certainly makes the most challenging lawns much easier by comparison. Faced with uneven terrain, you can power through without much effort if you have a self-propelled lawn mower. If you want to put in the least amount of effort when lawn mowing, a gas mower is definitely for you.

What’s the bottom line? Choose an electric lawn mower if you have a small to medium-sized lawn that’s relatively level, and you want a piece of equipment that’s eco-friendly and low maintenance. Choose a gas lawn mower if you need the power to plow through rough terrains and large lawns, and don’t mind the noise and maintenance involved with gas mowers.

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