English for students of physics. Часть 2 (110

Through direct optical measurements, the team showed that light of different wavelengths in the 500-700nm region was "trapped" at different positions along the grating, consistent with computer simulations. To prepare the nanopattern gratings required "milling" 150nm wide rectangular grooves every 520nm along the surface of a 300-nm-thick silver sheet. 2._______.

"Metamaterials, which are man-made materials with feature sizes smaller than the wavelength of light, offer novel applications in nanophotonics, photovoltaic devices, and biosensors on a chip," said Filbert J. Bartoli, principal investigator, professor and chair of the Department of Electrical and Computer Engineering. "Creating such nanoscale patterns on a metal film allows us to control and manipulate F. _____ . The findings of this paper present an unambiguous experimental demonstration of rainbow trapping in plasmonic nanostructures, and represents an important step in this direction."

"This technology for slowing light at room temperature can be integrated with other materials and components, which could lead to novel platforms for optical G. ____. 3. ______, said Qiaoqiang Gan, who completed this work while a doctoral candidate at Lehigh University, and is now an assistant professor in the Department of Electrical Engineering , State University of New York at Buffalo.

The study was funded by the National Science Foundation. 4. ______.

I. Fill in the terms: metamaterials, photons, circuits, grooves, trapping, light propagation, broadband (A - G).

II. Fill in the missing phrase:

a.It is published in the current issue of the Proceedings of the National Academy of Sciences.

b.The findings hold promise for improved data storage, optical data processing, solar cells, bio sensors and other technologies.

c. The ability of surface plasmons to concentrate light within nanoscale

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dimensions makes them very promising for the development of biosensors on chip and the study of nonlinear optical interactions

5.While intrinsic metal loss on the surface of the metal did not permit the complete "stopping" of these plasmons, future research may look into compensating this loss in an effort to stop light altogether.

III.Answer the questions:

-Describe the way to slow down light.

-What are metamaterials?

-Summarize the possible uses of slow light. Use any extra information you

can.

IV. Speaking. Introducing the innovation in your company.

Role-play an IT company meeting in which you, being a member of the Research and Development Department, are going to point out the benefits of the “trapping light” technology for the company. Try to convince the managers to pay special attention to this innovation.

Unit VI. Laser Could Rival Sun's Energy (From Live Science)

Ed Moses, the director of a high-energy physics adventure to produce the world's most powerful laser, talks of the "grand challenge'' that has consumed him for the past five years, namely to create in a laboratory the energy found at the center of the sun.

In a building the size of a football stadium, engineers have assembled the framework for a network of 192 laser beams, each traveling 1,000 feet to converge simultaneously on a target the size of a pencil eraser. The trip will take one-thousandth of a second during which the light's energy is amplified many billions of times to create a brief laser pulse 1,000 times the electric generating power of the United States. The goal is to create unimaginable heat -- 180 million

degrees Farenheit -- and intense pressure from all directions on a BB-size

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hydrogen fuel pellet, compressing it to one-thirtieth of its size. The result, the scientists hope, will be a fusing of atoms so that more energy is released than is generated by the laser beams, something scientists call fusion ignition. It is what happens when a hydrogen bomb explodes.

Four of the beams have been tested. When completed in 2008, the National Ignition Facility, or NIF, as the laser at the Lawrence Livermore National Laboratories is called, will dwarf many times over any laser to date. It will provide a platform for many experiments in high-energy and high-density physics, from learning more about the planets and stars to advancing the elusive hunt for fusion energy to generate electric power, Moses says. "You have to think of this like the Hubble,'' he says, referring to the space telescope. "It's a place where you will see things and do things that you couldn't do anywhere else.''

If NIF achieves fusion ignition, it will for the first time in a laboratory simulate the pressures and heat of a nuclear explosion, allowing nuclear weapons scientists to study the performance and readiness of the country's aging nuclear arsenal without actually detonating a nuclear device. The NIF laser "is essential to assessing the potential performance of nuclear weapons,'' says Energy Secretary Samuel Bodman. He says the experiments will help determine the effects of aging on warheads and help assure they will work as expected, should they be needed.

There have been other lasers, including a 10-beam Livermore project called Nova. NIF will produce 40 times to 60 times more energy. "It's the difference between a car and a jet engine,'' Moses says. For many supporters the "pass-fail'' is whether the NIF lasers will achieve fusion ignition.

"We never intended to spend $5 billion to $6 billion to build a laser facility for ...

civilian research,'' says Sen. Pete Domenici, R-N.M., chairman of the Senate subcommittee that funds the NIF program.

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Among some people, fusion ignition "has become the poster child for NIF being successful'' and that shouldn't be the case, counters George Miller, a former nuclear weapons designer and bomb tester who heads the project. He says there are many other experiments for which NIF will be valuable to nuclear weapons scientists.

The new team tackled a variety of problems. By 2003, the dust issue was solved by building a massive clean room and installing the optics in modular dust-free units. Engineers found new ways to produce the thousands of highly polished pieces of laser glass. A faster way was found to grow high-quality crystals that convert the beams to ultraviolet just before they strike the target.

And with four of the planned 192 beams operating, new tests suggested strongly that when the system was fully operating, enough energy would be produced to -- theoretically, at least -- achieve ignition.

Last year, however, a new complication emerged -- not over the laser but the peasize pellet that contains the hydrogen fuel that will be ignited by the lasers to achieve fusion ignition. Could the pellet be manufactured to the required specifications? Once its shell was to be made of plastic, but that idea was abandoned. Now the choice is beryllium, a metallic element that can withstand intense heat, is molecularly stable and is a good conductor. It still is uncertain whether beryllium can be machined to specification, according to technicians who have monitored the program. Last year Congress directed another outside review to report how the development of a beryllium target might affect NIF's timetable.

Like previous challenges in the project's history, the beryllium issue will be resolved, Miller and Moses believe. While the massive laser may one day have a broad range of scientific uses -- some not even envisioned by today's scientists -- the immediate focus remains assuring the reliability of the nation's nuclear

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arsenal without actually testing the weapons (Retrieved from: http://www. livescience.com/282-laser-rival-sun-energy.html).

I. Find the words in the article that might correspond to these definitions:

1.________ the quality, condition, or fact of being exact and accurate. 2.________ an essential supporting structure of a building, vehicle, or object. 3._________ make (something) more marked or intense.

4._________ a small, rounded, compressed mass of a substance. 5._________ the action of setting something on fire or starting to burn.

6.__________ a standard for the hardware of a computer system, which determines what kinds of software it can run.

7._________ the explosive head of a missile, torpedo, or similar weapon. 8._________ a department of an institution with a specific function. 9._________ a circumstance that complicates something; a difficulty. 10._________ remain undamaged or unaffected by; resist.

II.Decide whether the statements are true or false.

-The laser that could rival the Sun has recently been created.

-To achieve fusion ignition it is necessary to create heat and pressure on a fuel pellet.

-The NIF is believed to be a unique project because of its space telescope.

-The NIF laser is going to be used for testing weapons.

-Civilian research is the Senate's top priority.

-New crystals have been grown to eliminate the problem of dust.

-Due to the NIF achieving ignition is no longer mere theory nowadays.

-A new pellet has already been designed to meet the specifications.

III. Summarize the following points:

-The kind of construction that harbours the NIF laser;

-The possible uses of the NIF laser;

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-The principle of its work;

-The reason why the Government has invested so much in the project;

-The difficulties the researchers have faced.

-Make up an abstract of the article (6 – 8 sentences).

IV. Discussion. Preliminary work. Find out more about the possible non-military laser uses.

Discussion topic. "We never intended to spend $5 billion to $6 billion to build a laser facility for civilian research''. Would you personally intend to do that if you were a senator? Which is more important, civilian or military research? Give your reasons.

Unit VII

I. Read the article, suggest the idea of the title for it.

II. Match the parts of the article with the subheadings: Better than Bulbs, Happy Accident, New Dilemma, Judging by Appearance, Likely Alternative.

1.________ The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork. An accidental discovery has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The miniature breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention obsolete. LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.

2. _________ Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. That's less than 1/1000th the width of a human hair. Quantum dots contain anywhere from 100 to 1,000 electrons. They're easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bower's particular batch was exceptionally small, containing only 33 or 34 pairs of atoms. When you shine a light on quantum dots or apply electricity

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to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened. "I was surprised when a white glow covered the table," Bowers said. "The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow."

3.__________ Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light similar to a regular light bulb. The new device gives off a warm, yellowish-white light that shines twice as bright and lasts 50 times longer than the standard 60 watt light bulb. Until the last decade, LEDs could only produce green, red, and yellow light, which limited their use. Then came blue LEDs, which have since been altered to emit white light with a lightblue hue.

4._________ LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025. LEDs don't emit much heat, so they're also more energy efficient. And they're much harder to break.

5._________ Other scientists have said they expect LEDs to eventually replace standard incandescent bulbs as well as fluorescent and sodium vapor lights. If the new process can be developed into commercial production, light won't come just from newfangled bulbs. Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white. One big question remains: When a brilliant idea pops into your mind in the future, what will appear over your head?

III. Vocabulary Practice

A. Give synonyms using vocabulary units from the article: old-fashioned, a set of similar things, brilliance, give off, change, brand new.

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B. Explain the following: LED lighting, flashlight, a graduate student, a quantum dot, lumpy, efficient.

IV. Are the statements below true or false?

1.Small discoveries can give life to new big trends.

2.To excite the bundles of energy electricity is required.

3.The new invention doesn't live up to the Edison's bulb.

4.Quantum dot mixtures didn't use to produce white light.

V.Answer the questions:

-What has led to the discovery?

-How is light produced due to the quantum dots?

-What colours can be produced by the new device?

-Speak about the use of quantum dot mixtures.

-Why do they tend to operate less expensively?

VI. What do you personally think about the invention? Is its future as colourful and radiant as shown in the article? Discuss it with your partner.

VII. Give the account of the discovery from the point of view of Michael Bowers (about 12 sentences).

Unit VIII. Electric properties of matter. Piezoelectricity [pietsəuelik’tricəti]

1. Some solids, notably certain crystals, have permanent electric polarization. Other crystals become electrically polarized when subjected to stress. In electric polarization, the centre of positive charge within an atom, molecule, or crystal lattice element is separated slightly from the centre of negative charge. Piezoelectricity (literally “pressure electricity”) is observed if a stress is applied

to a solid, for example, by bending, twisting, or squeezing it. If a thin slice of

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quartz is compressed between two electrodes, a potential difference occurs; conversely, if the quartz crystal is inserted into an electric field, the resulting stress changes its dimensions. Piezoelectricity is responsible for the great precision of clocks and watches equipped with quartz oscillators. It also is used in electric guitars and various other musical instruments to transform mechanical vibrations into corresponding electric signals, which are then amplified and converted to sound by acoustical speakers.

2.A crystal under stress exhibits the direct piezoelectric effect; a polarization P, proportional to the stress, is produced. In the converse effect, an applied electric field produces a distortion of the crystal, represented by a strain proportional to the applied field. The basic equations of piezoelectricity are P = d × stress and E = strain/d. The piezoelectric coefficient d (in metres per volt) is approximately 3 × 10−12 for quartz, 5 × −10−11 for ammonium dihydrogen phosphate, and 3 × 10−10 for lead zirconate titanate.

3.For an elastic body, the stress is proportional to the strain—i.e., stress = Ye × strain. The proportionality constant is the coefficient of elasticity Ye, also called Young's modulus for the English physicist Thomas Young. Using that relation, the induced polarization can be written as P = dYe × strain, while the stress required to keep the strain constant when the crystal is in an electric field is stress = −dYeE. The strain in a deformed elastic body is the fractional change in the dimensions of the body in various directions; the stress is the internal pressure along the various directions. Both are second-rank tensors, and, since electric field and polarization are vectors, the detailed treatment of piezoelectricity is complex. The equations above are oversimplified but can be used for crystals in certain orientations.

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4.The polarization effects responsible for piezoelectricity arise from small displacements of ions in the crystal lattice. Such an effect is not found in crystals with a centre of symmetry. The direct effect can be quite strong; a potential V = Yedδ/ε0K is generated in a crystal compressed by an amount δ, where K is the dielectric constant. If lead zirconate titanate is placed between two electrodes and a pressure causing a reduction of only 1/20th of one millimetre is applied, a 100,000-volt potential is produced. The direct effect is used, for example, to generate an electric spark with which to ignite natural gas in a heating unit or an outdoor cooking grill.

5.In practice, the converse piezoelectric effect, which occurs when an external electric field changes the dimensions of a crystal, is small because the electric fields that can be generated in a laboratory are minuscule compared to those existing naturally in matter. A static electric field of 106 volts per metre produces a change of only about 0.001 millimetre in the length of a one-centimetre quartz crystal. The effect can be enhanced by the application of an alternating electric field of the same frequency as the natural mechanical vibration frequency of the crystal. Many of the crystals have a quality factor Q of several hundred, and, in the case of quartz, the value can be 106. The result is a piezoelectric coefficient a factor Q higher than for a static electric field. The very large Q of quartz is exploited in electronic oscillator circuits to make remarkably accurate timepieces. The mechanical vibrations that can be induced in a crystal by the converse piezoelectric effect are also used to generate ultrasound. The reflected sound is detectable by the direct effect. Such effects form the basis of ultrasound systems used to fathom the depths of lakes and waterways and to locate fish. Ultrasound has found application in medical imaging (e.g., fetal monitoring and the detection of tumours). The use of ultrasound makes it possible to produce detailed pictures of organs and other internal structures because of the variation in the reflection of

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