English Study Group Online

Clock

Look it up


NHẬP TỪ CẦN TRA VÀO Ô

Chọn từ điển theo yêu cầu:

Powered by Blogger.

TRUYỆN CƯỜI

Total Pageviews

Monday, April 14, 2014


There are more than 250,000 words in the Oxford English dictionary. This number does not include slang or technical words. However, a good English speaker would normally use only 15,000 to 20,000 of these words. If you think your vocabulary is weak, a little effort everyday over a six to nine month period can go a long way in improving it.



Here are top ten vocabulary improvement tip

1. Make reading the newspaper a daily ritual. You may be comfortable reading a particular section but make an effort to read different articles on every page. The editorial page is highly recommended not only for vocabulary but also for structuring and presenting thought.

2. Make it a habit to read a new book every week. It is not surprising that those who read a lot develop a good vocabulary. You can consider becoming a member of the local library. Make a list of wordsthat are new to you and look up their meanings in the dictionary.

3. Watching English movies and television shows is important for improving English and learning new English words. The best part about watching English videos is that you can learn the correct pronunciation as well.

4. Use vocabulary cards. Vocabulary cards are used by students who are trying to learn many words in a short period of time. You can make your own cards by writing the word on one side and the meaning on the other side of a square piece of paper. It is a convenient tool to learn new words in your free time

5. Use the internet. The internet is an unlimited resource for reading material. Pick up a topic of your choice and search for articles about it. You will come across plenty of material to read, which you might find interesting, and importantly, will also introduce you to new words. Be sure to look them up in a dictionary.

6. Don’t forget the new words. The best way to ensure that you never forget the new words you learn is to start using them in your day to day conversation. Do not try to force them into a conversation but do use them if you think they are appropriate.

7. Learn pronunciation. Most dictionaries provide us with pronunciations of words using phonetic symbols. It is important to learn the sounds that correspond to these phonetic symbols, in order to become comfortable pronouncing new words.

8. Learning in groups is always more fun. If you have friends who also want to improve their vocabulary, then you can form a group and share new words with each other. You can meet at regular intervals and measure your progress.

9. Learn the root words. Root words are words from which words grow with the addition of prefixes and suffixes. For example: The word vocabulary is derived from the Latin root word ‘voc’, which means 'word' or 'name'. Other words like advocacy, vocal and vociferous are also derived from the same root word. 

Hence, if you can recognize some root words, you will get a fair idea of many derived words. Check out our list of common root words.

10. Keep revising. While it is important to read and learn new words, it is equally important to revise what you have learnt. Fix a particular day of the week to revise all the words you have learnt in that week and add them to your daily vocabulary.


Sunday, April 13, 2014
Graphene transistors visible on a piece of flexible plastic. Graphene is not only the hardest material in the world, but also one of the most pliable.


By Nick Bilton

I just want to say one word to you. Just one word. 

No, fans of “The Graduate,” the word isn’t “plastics.” 

It’s “graphene.” 

Graphene is the strongest, thinnest material known to exist. A form of carbon, it can conduct electricity and heat better than anything else. And get ready for this: It is not only the hardest material in the world, but also one of the most pliable. 

Only a single atom thick, it has been called the wonder material. 

Graphene could change the electronics industry, ushering in flexible devices, supercharged quantum computers, electronic clothing and computers that can interface with the cells in your body.

While the material was discovered a decade ago, it started to gain attention in 2010 when two physicists at the University of Manchester were awarded the Nobel Prize for their experiments with it. More recently, researchers have zeroed in on how to commercially produce graphene. 

The American Chemical Society said in 2012 that graphene was discovered to be 200 times stronger than steel and so thin that a single ounce of it could cover 28 football fields. Chinese scientists have created a graphene aerogel, an ultralight material derived from a gel, that is one-seventh the weight of air. A cubic inch of the material could balance on one blade of grass.

“Graphene is one of the few materials in the world that is transparent, conductive and flexible — all at the same time,” said Dr. Aravind Vijayaraghavan, a lecturer at the University of Manchester. “All of these properties together are extremely rare to find in one material.”

So what do you do with graphene? Physicists and researchers say that we will soon be able to make electronics that are thinner, faster and cheaper than anything based on silicon, with the option of making them clear and flexible. Long-lasting batteries that can be submerged in water are another possibility. 

In 2011, researchers at Northwestern University built a battery that incorporated graphene and silicon, which the university said could lead to a cellphone that “stayed charged for more than a week and recharged in just 15 minutes.” In 2012, the American Chemical Society said that advancements in graphene were leading to touch-screen electronics that “could make cellphones as thin as a piece of paper and foldable enough to slip into a pocket.”

Dr. Vijayaraghavan is building an array of sensors out of graphene — including gas sensors, biosensors and light sensors — that are far smaller than what has come before. 

And last week, researchers at the Samsung Advanced Institute of Technology, working with Sungkyunkwan University in South Korea, said that Samsung had figured out how to create high-quality graphene on silicon wafers, which could be used for the production of graphene transistors. Samsung said in a statement that these advancements meant it could start making “flexible displays, wearables and other next-generation electronic devices.”

Sebastian Anthony, a reporter at Extreme Tech, said that Samsung’s breakthrough could end up being the “holy grail of commercial graphene production.”

Samsung is not the only company working to develop graphene. Researchers at IBM, Nokia and SanDisk have been experimenting with the material to create sensors, transistors and memory storage.

When these electronics finally hit store shelves, they could look and feel like nothing we’ve ever seen.
James Hone, a professor of mechanical engineering at Columbia University, said research in his lab led to the discovery that graphene could stretch by 20 percent while still remaining able to conduct electricity. “You know what else you can stretch by 20 percent? Rubber,” he said. “In comparison, silicon, which is in today’s electronics, can only stretch by 1 percent before it cracks.”

He continued: “That’s just one of the crazy things about this material — there’s really nothing else quite like it.” 

The real kicker? Graphene is inexpensive.

If you think of something in today’s electronics industry, it can most likely be made better, smaller and cheaper with graphene.

Scientists at the University of California, Berkeley made graphene speakers last year that delivered sound at quality equal to or better than a pair of commercial Sennheiser earphones. And they were much smaller.
Another fascinating aspect of graphene is its ability to be submerged in liquids without oxidizing, unlike other conductive materials.

As a result, Dr. Vijayaraghavan said, graphene research is leading to experiments where electronics can integrate with biological systems. In other words, you could have a graphene gadget implanted in you that could read your nervous system or talk to your cells.
But while researchers believe graphene will be used in next-generation gadgets, there are entire industries that build electronics using traditional silicon chips and transistors, and they could be slow to adopt graphene counterparts.

If that is the case, graphene might end up being used in other industries before it becomes part of electronics. Last year, the Bill and Melinda Gates Foundation paid for the development of a graphene-based condom that is thin, light and impenetrable. Carmakers are exploring building electronic cars with bodies made of graphene that are not only protective, but act as solar panels that charge the car’s battery. Airline makers also hope to build planes out of graphene. 

If all that isn’t enough, an international team of researchers based at M.I.T. has performed tests that could lead to the creation of quantum computers, which would be a big market of computing in the future.
So forget plastics. There’s a great future in graphene. Think about it.