English Recordings

ALUMINA-BASED CERAMICS

Ceramic tool materials, introduced in the early 1950s, consist primarily of fine-grained, high-purity aluminium oxide. They are cold-pressed into insert shapes under high pressure and sintered at high temperature; the end product is referred to as white, or cold-pressed, ceramics. Additions of titanium carbide and zirconium oxide help improve properties such as toughness and thermal-shock resistance.
Alumina-based ceramic tools have very high abrasion resistance and hot hardness. Chemically, they are more stable than high-speed steels and carbides, so they have less tendency to adhere to metals during cutting and a correspondingly lower tendency to form a built-up edge. Consequently, in cutting cast irons and steels, good surface finish is obtained with ceramic tools. However, ceramics lack toughness, and their use may result in premature tool failure by chipping or catastrophic failure.
Ceramic inserts are available in shapes similar to the shapes of carbide inserts. They are effective in high-speed, uninterrupted cutting operations, such as finishing or semifinishing by turning. To reduce thermal shock, cutting should be performed either dry or with a copious amount of cutting fluid, applied in a steady stream. Improper or intermittent applications of the fluid can cause thermal shock and fracture of the ceramic tool.
Ceramic tool shape and setup are important. Negative rake angles (large included angles) are generally preferred in order to avoid chipping due to the poor tensile strength of ceramics. Tool failure can be reduced by increasing the stiffness and damping capacity of machine tools, mountings, and workholding devices, thus reducing vibration and chatter.

Cermets. Black, or hot-pressed, ceramics were introduced in the 1960s. They typically contain 70% aluminium oxide and 30% titanium carbide, and are also called "cermets" (from ceramic and metal). Other cermets contain molybdenum carbide, niobium carbide, and tantalum carbide. Although they have chemical stability and resistance to built-up edge formation, their brittleness and high cost have been a problem.
Further refinements of these tools have resulted in improved strength, toughness, and reliability. Their performance is somewhere between that of ceramics and carbides and has been particularly suitable for light roughing cuts and high-speed finishing cuts. Chip-breaker features are important for cermet inserts. Although cermets can be coated, the benefits of coatings are somewhat controversial; the improvement in wear resistance appears to be marginal.

Cutting tool material - Diamond

Of all known materials, the hardest substance is diamond. It has low friction, high wear resistance, and the ability to maintain a sharp cutting edge. Diamond is used when good surface finish and dimensional accuracy are required, particularly with soft nonferrous alloys and abrasive nonmetallic materials. Single-crystal diamond of various carats is used for special applications, such as machining copper-front precision optical mirrors for the Strategic Defense Initiative program.
Because diamond is brittle, tool shape and sharpness are important. Low rake angles (large included angles) are generally used to provide a strong cutting edge. Special attention should be given to proper mounting and crystal orientation in order to obtain optimum tool life. Wear may occur through microchipping (caused by thermal stresses and oxidation) and through transformation to carbon (caused by the heat generated during cutting).
Single-crystal diamond tools have been largely replaced by polycrystalline-diamond (PCD) tools, which are also used as wire-drawing dies for fine wire. These materials consist of very small synthetic crystals, fused by a high-pressure, high-temperature process to a thickness of about 0.5 to 1 mm and bonded to a carbide substrate; the result is similar to CBN tools. The random orientation of the diamond crystals prevents the propagation of cracks through the structure, significantly improving its toughness.
Diamond tools can be used satisfactorily at almost any speed, but are most suitable for light, uninterrupted finishing cuts. In order to minimize tool fracture, the single-crystal diamond must be resharpened as soon as it becomes dull. Because of its strong chemical affinity, diamond is not recommended for machining plain-carbon steels or titanium, nickel, and cobalt-based alloys. Diamond is also used as an abrasive in grinding and polishing operations and as coatings.

27.
When faced with things that are too big to sense, we comprehend them by adding knowledge to the experience.
The first appearance of a shining star in a darkening evening sky can take you out into the universe if you
combine what you see with the twin facts that the star is merely one of the closest of the galaxy’s 200 billion stars and that its light began traveling decades ago. The smell of gasoline going into a car’s tank during a refueling stop, when combined with the fact that each day nearly a billion gallons of crude oil are refined and used in the United States, can allow our imagination to spread outward into the vast global network of energy trade and politics.

28.
The first experiments in television broadcasting began
in France in the 1930s, but the French were slow to
employ the new technology. There were several reasons
for this hesitancy. Radio absorbed the majority of state resources, and the French government was reluctant to shoulder the financial burden of developing national networks for television broadcasting. Television
programming costs were too high, and program output correspondingly low. Poor distribution combined with minimal offerings provided little incentive to purchase the new product. Further, television sets were priced beyond the means of a general public whose modest living standards, especially in the 1930s and 1940s, did not allow the acquisition of luxury goods.
Ideological influences also factored in; elites in particular were skeptical of television, perceiving
it as a messenger of mass culture and Americanization.

29.
A violin creates tension in its strings and gives each of them an equilibrium shape: a straight line. A tight violin string can be viewed as composed of many individual pieces that are connected in a chain as in the above two figures. When the string is straight, as in
Figure 1, its tension is uniform, and the two outward forces on a given piece sum to zero; they have equal magnitudes and point in opposite directions. With no net forces acting on its pieces, the string is in equilibrium.
But when the string is curved, as in Figure 2, the outward forces on its pieces no longer sum to zero.
Although the string’s uniform tension still gives those outward forces equal magnitudes, they now point in slightly different directions, and each piece experiences a zero net force. The net forces on its pieces are
restoring forces, which will cause the string to vibrate and thus make sounds.

24.
While the fine art object is valued because it is unique, it is also valued because it can be reproduced
for popular consumption. For example, Van Gogh’s paintings
have been reproduced endlessly on posters, postcards, coffee mugs, and T-shirts. Ordinary consumers can own a copy of the highly valued originals. Therefore, the value of
the original results not only from its uniqueness but from its being the source from which reproductions are made.
The manufacturers who produce art reproductions and the consumers who purchase and display them give value to the work of art by making it available to many people as an item of popular culture.

25.
There are some people who believe that no one should be trusted. They usually feel this way because their
behavior compels others to lie to them. In other words, they make it difficult for others to tell them the truth because they respond rudely or emotionally to people who
tell the truth. If others see how angry, hurt, or hateful you become when they tell you the truth, they will avoid telling it to you at all costs. If you are known as someone who is easily offended, you will never know what others are really
thinking or feeling because they will distort the truth to escape from your negative reaction. If you demand that children tell you the truth and then punish them because it
is not very satisfying, you teach them to lie to you to protect themselves.

26.
One of the main principles I follow when I draw outside is not to select a subject that is too difficult or odd. I try to stay away from houses or barns that have unusual angles of the roof, or objects that look incorrect in size, perspective, or design.
If the subject is confusing when you look at it, it will be more confusing when you attempt to draw it. I know a beautiful barn where the corners are not at right angles. No matter how many times I have drawn it, the perspective does
not look right. If I were to make an accurate drawing of this barn and put it in a show, I’m sure I would get all kinds of criticism for my poor perspective. I would not be there to tell my critics that the barn is actually constructed this way.
So, I stay away from subjects that do not look right to me.

21.
Many social scientists have believed for some time that birth order directly affects both personality
and achievement in adult life. In fact, people have been
using birth order to account for personality factors such
as an aggressive behavior or a passive temperament. One
might say, “Oh, I’m the eldest of three sisters, so I can’t
help that I’m so overbearing,” or “I’m not very successful
in business, because I’m the youngest child and thus less aggressive than my older brothers and
sisters.” Recent studies, however, have proved this belief to be false. In other words, birth order may define your role within a family, but as you mature into adulthood, accepting other social roles, birth order becomes insignificant.

22.
You may think that moving a short distance is so easy that you can do it in no time with little effort. You may decide to use your own car because you think that you don’t need the services of a moving company. Well, you might be wrong. You are under the false impression that you do not have as many items to pack as you really do.
You find out too late that your car cannot carry as much as you thought it could. So, it takes you far more
trips to your new home than you thought it would. There is also the possibility of damaging your stuff, some of it valuable. All these things considered, it might be better
to ask for the services of a moving company.

23.
Roman doll-makers continued to use technology developed by the Egyptians and Greeks, but in line with the artistic sensibilities of their culture, they were constantly trying to make dolls more elegant and
beautiful. One doll, found near Prati in Rome, was made of ivory and lay beside her owner who had died at the age of eighteen. The huge growth in the understanding of civilization raised awareness of other important roles of trade. Next to the doll was a small box, also made of ivory, containing tiny combs and a silver mirror.
The doll had rings on her fingers and held a tiny key,
which unlocked the box. Like children today, the
younger members of Roman civilization would have
dressed and undressed their dolls, and decorated their hair
and fingers according to the latest fashions.

18.
This is different from all other markets in that people do not buy things here such as clothes, shoes, or cars.
Thanks to this, people can easily exchange one country’s money with that of another. People desire to make such exchanges for many reasons. Some are concerned with
the import or export of goods or services between one country and another. Others wish to move capital from one area to another. Still others may want to travel to a
foreign country. This is incredibly important to the global economy. This gets influenced by a real world event, and has an impact on the economy of a nation, causing the
value of its money to rise and fall.

19.
Flying over rural Kansas in an airplane one fall evening was a delightful experience for passenger Walt Morris.
He watched the twinkling farmhouse lights below.
Suddenly, the peace of the evening was broken when the plane’s landing lights started flashing on and off. ‘What’s happening?’ he wondered as he gripped the armrests.
As the pilot was about to make an announcement, he thought, ‘This is it. He’s going to tell us we’ve got a
major problem.’ Instead, he told the passengers, “In case you’re worried about the flashing lights outside the
plane, I’m sending a signal to my kids.” He was relieved to hear the continued announcement: “They’re at
home over on that hill to the left, and they just sent me a Morse code message saying, ‘Good night, Dad.’ ”

20.
If you are worrying about money when you are away, your enjoyment will suffer. Plan your budget in advance
to give yourself time to research the costs fully. If you cannot get confirmed prices, get as many estimates as you can. Note the best price and the worst price and budget
in between the two. Ideally, the budgeted figures will work out just about right. If they don’t, you will have to use your emergency fund to cover basic expenses such as food, transport, and accommodation, and there will be less money available for an unexpected situation that necessitates a sudden change of plan. So, be sure to make your
budget realistic, so that you can be confident that you will be able to pay for all aspects of the trip.

Ask yourself a question. How much time do you spend studying English everyday? I’m not talking about the studying you must do for school, I’m talking about the time that you spend on your own. If you are like most people, you study a lot one day, or for a few days, and then do nothing at all for several days. Then you start to feel guilty for not studying, so you decide that you are going to change that pattern again. You study very hard for a while and then eventually quit again.

Studying for 20 minutes every day is much better than studying for 2 hours and 20 minutes once a week. Your brain can only take in a certain amount of information at one time. If you study for longer than that at one time then you will forget much of what you have learned. Also, if you study for a short time each day, your brain has a chance to think about what you just learned, and then practice it before you study again the next day. Make studying a habit. Don’t have an all or nothing attitude. 10 minutes is still better than nothing. Always remember that.

Listen to a podcast, write a comment, read a blog. Just make sure you do something every day. If you can spend more time that is great, but make sure you can do something every single day. I challenge you to study English for 20 min every day for the next 30 days. You can’t do nothing one day and then 40 minutes the next. That doesn’t count. The challenge is that you must do it every single day for 30 days. Do you think you can do it? I know you can.

If someone is leading a “double life” it means that in one area of their life they act a certain way and portray a certain image, whereas in another area of their life they act and behave completely differently; hence the term “double life”. Usually the reason that the person needs to portray two different characters is that they have some secret part of their life that they don’t want other people to know about.

As an example, imagine a really nice mother who is a great wife, takes great care of her kids and has a nice job. Everyone thinks she perfect. Secretly however, she dates several men behind her husband’s back and tells no one about it. This woman is leading a double life.

Sometimes teens lead “double lives” because their parents won’t allow them to do certain things that their friends do. They seem like perfect kids in front of their parents, but do all sorts of “bad” things behind their parent’s backs.

This expression means to handle a situation in a kind and ethical way instead of retaliating and seeking revenge.

Here is a common situation where this expression is used:

Imagine your boss was in a bad mood one day and started yelling at you for no good reason and complaining about your work. You’d probably be upset by this and might want to retaliate by saying something negative to him. Let’s say that you discuss this with your friend and your friend says to you; “He’s just in a bad mood. Of course he shouldn’t have yelled at you, but if you get upset and yell back then you are just as bad as he is. You should take the high road and forget about it.”

Imagine your ex-girlfriend sees you and tells you that she never loved you and hated the whole time you were together. You could retaliate by saying something horrible to her, or you could take the high road by disregarding what she said or saying something like, “I’m sorry you feel that way”.

I know from experience it’s difficult to take the high road (I don’t always do it) but it’s certainly something we should all try to do.

Cognitive psychology is the branch of psychology that studies mental processes including how people think, perceive, remember and learn. As part of the larger field of cognitive science, this branch of psychology is related to other disciplines including neuroscience, philosophy, and linguistics.

The core focus of cognitive psychology is on how people acquire, process and store information. There are numerous practical applications for cognitive research, such as ways to improve memory, how to increase decision-making accuracy, and how to structure educational curricula to enhance learning.

Until the 1950s, behaviorism was the dominant school of thought in psychology. Between 1950 and 1970, the tide began to shift against behavioral psychology to focus on topics such as attention, memory, and problem solving. Often referred to as the cognitive revolution, this period generated considerable research including processing models, cognitive research methods and the first use of the term "cognitive psychology."

How is Cognitive Psychology Different?

* Unlike behaviorism, which focuses only on observable behaviors, cognitive psychology is concerned with internal mental states.
* Unlike psychoanalysis, which relies heavily on subjective perceptions, cognitive psychology uses scientific research methods to study mental processes.

Who Should Study Cognitive Psychology?

Because cognitive psychology touches on many other disciplines, people in a number of different fields often study this branch of psychology. The following are just a few of those who may benefit from studying cognitive psychology.

* Students interested in behavioral neuroscience, linguistics, industrial-organizational psychology, artificial intelligence and other related areas.
* Teachers, educators and curriculum designers can benefit by learning more about how people process, learn, and remember information.
* Engineers, scientists, artists, architects and designers can all benefit from understanding internal mental states and processes.