Grammar: The Adjective and the Participle as an Attribute

Unit 1

Grammar: The Adjective and the Participle as an Attribute

Word List:

1. guest-host	«гость-хозяин» – один из эффектов в жидких кристаллах
2. to be doped with	достраиваться
3. elevated temperatures	повышение температуры
4. molecular ordering	упорядоченное расположение молекул
5. to be bonded together, to be crosslinked	соединяться, цепляться
6. crosslinking	образование поперечных межмоле­куляр­ных связей; структурирование, сшивание полимеров
7. to be aligned	выравниваться, устанавливаться в ряд/линию
8. straight-forward	прямой, простой
9. with respect to	по отношению
10. second-order nonlinear optical effects	нелинейные оптические эффекты второго порядка
11. submicrometer	нанометровый диапазон волн, 10–9 м
12. optical coefficients	коэффициент отражения и коэффициент преломления
13. non-centrosymmetrical arrangement	расположение, не симметричное относительно центральной оси
14. gradual relaxation	постепенный отход/уход
15. orientation = arrangement	расположение
16. reactive site	месторасположение в результате химической реакции

“Guest-Host” Systems

The move toward small-scale, submicrometer, integrated optical circuits has revealed fundamental disadvantages in the use of traditional inorganic materials for the required nonlinear optical devices. Organic chemistry has promised materials with not only large nonlinear optical coefficients but also the structural properties required for the production of these small-scale devices. The simplicity of the so-called guest-host system, in which a polymeric matrix is doped with molecules possessing high nonlinear optical coefficients, has made such materials a popular choice in the production of many prototype systems. An external electric field, applied at elevated temperatures, induces the non-centrosymmetrical arrangement of nonlinear molecules required for second-order nonlinear optical effects. However, this molecular ordering has been shown to be unstable resulting in a gradual relaxation in the induced orientation.

Possibly the most promising alternative to the straight-forward guest-host system is to chemically functionalize the guest molecule by generating several reactive sites within its structure. The idea behind such a development is that once aligned, the nonlinear molecules can be chemically bonded together (crosslinked) to form a long-ranged network. Such a network will dramatically reduce the mobility of the nonlinear molecules and thereby preserve the non-centrosymmetrical arrangement.

The stability of the induced orientation of these materials has already been demonstrated with respect to electro-optic modulation devices. The subject of the work being done is a study of the optically nonlinear guest molecule with respect to its nonlinear optical properties and its crosslinking process.

Focused Practice

I. Answer the following questions:

1. What has the move toward small-scale optical circuits revealed?

2. Why is the so-called guest-host system a popular choice in the production of many prototype systems?

3. What is the most promising alternative to the straight-forward guest-host system?

4. What is the idea behind such a development?

5. Will a long-ranged network reduce the mobility of the nonlinear molecules?

6. What has already been demonstrated?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Guest-host systems.

Unit 2

Focused Practice

I. Answer the following questions:

1. What do Hall thrusters offer?

2. Why is there concern about contamination of the satellite surface?

3. Why is the charge exchange plasma of particular concern?

4. What do computer codes need verification from?

5. What are the methods used to understand the plasma behavior of the plumes of Hall thrusters?

6. Why is the PIC technique well-suited to simulate the plumes of electric propulsion devices?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: 1. Hall thrusters. 2. DSMC and PIC methods.

Unit 3

Grammar: Modal Verbs – would, should, could.
The Inversion

Word List:

1. cortex	кора больших полушарий головного мозга
2. motor cortex	часть коры головного мозга, которая отвечает за движение
3. owl monkey-dowroucouli	маленькая обезьянка с глазами, как у совы, обитающая в Южной Америке, ведущая ночной образ жизни. Относится к роду Aotus; вымирающий вид
4. soundproof	звуконепроницаемый
5. joystick	ручка управления
6. dispenser	разливочный автомат
7. plastic connector	пластиковый разъём
8. brain tissue	ткань мозга
9. spinal cord	спинной мозг
10. multijointed	многошарнирный
11. limb	конечность
12. prone	склонный к чему-либо
13. randomly, at random	наугад, наобум, случайно
14. a box of electronics	электронное устройство

Controlling Robots with the Mind

Belle, our tiny owl monkey, was seated in her special chair inside a soundproof chamber at our Duke University laboratory. Her right hand grasped a joystick as she watched a horizontal series of lights on a display panel. She knew that if a light suddenly shone and she moved the joystick left or right to correspond to its position, a dispenser would send a drop of fruit juice into her mouth. She loved to play this game. And she was good at it.

Belle wore a cap glued to her head. Under it were four plastic connectors. The connectors fed arrays of microwires - each wire finer than the finest sewing thread - into different regions of Belle’s motor cortex, the brain tissue that plans movements and sends instructions for enacting the plans to nerve cells in the spinal cord. Each of the 100 microwires lay beside a single motor neuron. When a neuron produced an electrical discharge - an “action potential” - the adjacent microwire would capture the current and send it up through a small wiring bundle that ran from Belle’s cap to abox of electronics on a table next to the booth. The box, in turn, was linked to two computers, one next door and the other half a country away.

In a crowded room across the hall, members of our research team were getting anxious. After months of hard work, they were about to test the idea that they could reliably translate the raw electrical activity in a living being’s brain - Belle’s mere thoughts - into signals that could direct the actions of arobot. Unknown to Belle on this spring afternoon in 2000, we had assembled a multijointed robot arm in this room, away from her view, that she wouldcontrol for the first time. As soon as Belle’s brain sensed a lit spot on the panel, electronics in the box running two real-time mathematical models would rapidly analyze the tiny action potentials produced by her brain cells. That lab computer would convert the electrical patterns into instructions that woulddirect the robot arm. Six hundred miles north, in Cambridge, Mass., adifferent computer would produce the same actions in another robot arm.

If they had done everything correctly, the two robot arms would behave as Belle’s arm did, at exactly the same time. We would have to translate her neuronal activity into robot commands in just 300 milliseconds - the natural delay between the time Belle’s motor cortex planned how she should move her limb and the moment it sent the instructions to her muscles. If the brain of a living creature could accurately control two dissimilar robot arms - despite the signal noise and transmission delays inherent in our lab network and the error-prone Internet - perhaps it could someday control a mechanical device or actual limbs in ways that would be truly helpful to people.

Finally the moment came. They randomly switched on lights in front of Belle, and she immediately moved her joystick back and forth to correspond to them. The robot arm moved similarly to Belle’s real arm. So did a computer in Cambridge.Belle and the robots moved in synchrony, like dancers choreographed by the electrical impulses sparking in Belle’s mind. Amid the loud celebration that erupted Cambridge, the teamcould not help thinking that this was only the beginning of a promising journey.

Focused Practice

I. Answer the following questions:

1. Who was the main participant of the experiment?

2. Where did the experiment take place?

3. What was the essence of that experiment?

4. What idea was the research team about to test?

5. What results did the research team expect from that experiment?

6. What was the final stage of the experiment?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The idea of the experiment.

Unit 4

Focused Practice

I. Answer the following questions:

1. What is magnetron sputtering?

2. What is the essential element of magnetron sputtering?

3. What does the planar magnetron source provide?

4. What does a large negative bias applied to the target accelerate?

5. How are secondary electrons and sputtered atoms emitted?

6. When is the efficiency of the generation of ions improved?

7. Where are large electric fields present in magnetron sputtering?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Magnetron sputtering.

Unit 5

Grammar: The Passive Voice

Word List:

1. strong particle-induced turbulence attenuation	ослабление сильной турбулентности (завихрения), обусловленной (наведенной, вызванной) частицами
2. wake	след (за телом в потоке), вихревая зона
3. eddy	вихревое движение, вихрь
4. particle Reynolds numbers	числа Рейнольдса для частиц
5. dissipating scales	значения рассеивания
6. center-plane	диаметральная плоскость
7. blower	нагнетатель воздуха
8. 10:1 contraction	десятикратное сужение

Particle-Induced Turbulence Attenuation

Experiments show that strong turbulence attenuation occurs with particle Reynolds numbers in the range of 10 to100. This indicates that the particles have long wakes which may have scales comparable to energy containing eddies in the flow. Distortion of eddies by these wakes is in some way responsible for the large reductions in turbulence levels. In a manner not fully understood, these wakes modify the turbulence so that energy is passed more rapidly from the energy containing eddies to the dissipating scales. This mechanism is studied by measuring the spatial structure and the dissipation rate for flows with strong particle-induced turbulence attenuation. In particular, the center-plane region of the fully-developed channel flow is examined. The experiments showed turbulence reductions by as much as a factor of 3 for particle mass loading ratios ranging up to 80 %.

The experiments were conducted in the vertical fully developed channel air-flow. The tunnel consists of an inlet and blower section, a flow conditioning section, a particle-feeding section, a 10:1contraction, a 5.2 m long development section, a test section, and a particle removal system. The particle feeding section provides a uniform and steady flow of particles that accelerate to their terminal velocity in the long development section. The development section also allows the gas flow to reach fully developed conditions. The acrylic test section has a channel half-width of
2 cm and a spanwise width of 46 cm. All experiments were conducted with a mean velocity of 10.5 m/s in the test section. The mean properties of the flow were largely unchanged by the addition of particles while the turbulence was changed substantially.

Focused Practice

I. Answer the following questions:

1. What do the experiments on turbulence show?

2. What do the particles have?

3. How do the long wakes modify the turbulence?

4. How is the mechanism studied?

5. What is examined in particular?

6. Where were the experiments conducted?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The vertical fully developed channel air-flow.

Unit 6

Focused Practice

I. Answer the following questions:

1. What have many types of pellet injectors been used for?

2. Has any previous attempt been made to produce tritium pellets?

3. What property of tritium is quite different from that of the other hydrogen isotopes?

4. Why is it desirable to demonstrate the production and acceleration of tritium pellets?

5. How do pneumatic guns produce pellets?

6. What did Milora and co-workers use a disk-shaped pellet carrier with pellet-size holes for?

7. What approach did Lafferranderie and co-workers use?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Problems unique to tritium

Unit 7

Grammar: The Attribute

Word List:

1. vapour state	парообразное состояние
2. atmosphere	единица измерения давления
3. kPa	килопаскаль (единица измерения давления)
4. vapour compression refrigeration equipment	оборудование компрессионного охлаждения пара
5. boiling point	точка кипения
6. freezing point	точка замерзания
7. versus	в зависимости от

Fundamental Characteristics of a Fluid

The triple point, normal boiling point and critical point parameters are fundamental characteristics of a fluid. The triple point is the state at which three phases (solid, liquid and vapour) coexist; it is virtually identical with the more often reported freezing point. The normal boiling point is simply the temperature at which the vapour pressure of a fluid is one standard atmosphere (101.325 kPa, 14.696 psia). As the vapour pressures of nearly all fluids are approximately parallel when plotted as the logarithm of pressure versusinverse temperature, the normal boiling point is a rough predictor of the vapour pressure at all temperatures. The critical point is the state at which the properties of the saturated liquid and vapour become indistinguishable: coexisting liquid and vapour are possible only at temperatures and pressures below the critical point values.

These parameters, often in the absence of any other information, are frequently used in screening many different compounds to select a more limited set for further study. For many applications they define the temperature limits for the use of a particular fluid. Clearly a refrigerant cannot be used below the triple point temperature. For many refrigeration applications, operation at sub-atmospheric pressures is avoided and, thus, the normal boiling point is a more practical lower limit. Vapour compression refrigeration equipment transports heat through condensation and evaporation (i.e. two-phase) processes and thus the critical point represents an upper temperature and pressure limit. The critical point parameters are the essential inputs to estimation techniques based on the law of corresponding states, which is the observation that, when scaled by the critical parameters, the properties of nearly all fluids are similar.

Focused Practice

I. Answer the following questions:

1. What are fundamental characteristics of a fluid?

2. Which state do three phases coexist at?

3. What is the normal boiling point?

4. When are the vapour pressures of nearly all fluids approximately parallel?

5. What is the critical point?

6. What does vapour compression refrigeration equipment do?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The normal boiling point.

Unit 8

Grammar: The Gerund

Word List:

1. axial flow	осевое течение, поток
2. enhancement ratio	степень интенсификации (теплообмена)
3. film condensation	плёночная конденсация
4. fine wire	тонкая проволока
5. fins	пластины радиатора
6. pressure gradient	градиент давления, перепад давления
7. surface tension	поверхностное натяжение
8. thermal conductivity	теплопроводность
9. wire wrap	монтаж проводов накруткой
10. curvature	кривизна
11. heat transfer	теплоотдача
12. refrigerant	охладитель
13. momentum	количество движения

Enhancing Film Condensation Heat Transfer

Several workers have investigated the simple and cheap method of enhancing film condensation heat transfer by winding fine wire on the surface of a condenser tube. The wire wrap does not act in the same way as fins and the wire does not need to have high thermal conductivity. Enhancement is due to thinning of the film between the adjacent turns of the wire caused by the surface tension induced pressure gradient in the condensate. The pressure gradient results from the fact that the interface curvature is higher nearer the wire and gives rise to axial flow of condensate towards the wire.

The presence of the curvature term in the momentum balance for the condensate film leads to significant complication in the theory and no complete solution of the problem has been published to date. An approximate approach involved some empiricism backed by experiments for R11 and ethanol, and naturally the final result was in broad agreement with the data for these fluids. Later measurements for steam do not agree with the approximate theory. The approximate theory has recently been amended to include condensate retention. The theory then involves no empiricism and is in general agreement with the tem data. However, while giving results of the correct order of magnitude, the modified theory predicts a dependence on wire diameter that is opposite to that reported by the approximate approach. There is a report on the first stage of a research programme aimed at resolving these discrepancies. Further theoretical investigations and experiments using a refrigerant are in progress.

The report is given on new measurements for condensation of steam on a horizontal, water-cooled, wire-wrapped tube. The wire diameter and pitch of winding were systematically varied and heat-transfer measurements made for a range of coolant flow rates for each wire diameter and pitch. Data, in the form of heat flux and vapour-to-surface temperature difference were used to determine enhancement ratios (ratio of heat flux for wire-wrapped tube to that for a plain tube at the same vapour-to-surface temperature difference).

The problem of condensation on wire-wrapped tubes is not yet fully understood. Further light should be shed on the problem by the new data using a refrigerant as condensing fluid.

Focused Practice

I. Answer the following questions:

1. What method of enhancing film condensation heat transfer have several earlier workers investigated?

2. What is enhancement due to?

3. Where is the interface curvature higher?

4. What did an approximate approach involve?

5. Does the modified theory involve any empiricism?

6. What is the research programme aimed at?

7. Is the problem of condensation on wire-wrapped tubes fully understood?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The approximate approach and the modified theory.

Unit 9

Focused Practice

I. Answer the following questions:

1. What was an experimental study conducted for?

2. What resulted in drastic reduction of hard zones at DMWs fabricated with EniCrFe-3 electrodes?

3. Can hard zones in DMWs be eliminated?

4. What is the optimum welding electrode composition?

5. Why have DMWs been used as transition joints for many years?

6. Where are the joints often made?

7. What can fabrication and metallurgical drawbacks of DMWs lead to?

8. What is the most troublesome drawback of DMWs?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Fabrication and metallurgical drawback of DMWs.

Unit 10

Focused Practice

I. Answer the following questions:

1. Why are the measurements of beam profiles in contact tests very complex?

2. Why do many variations of the beam profiles occur?

3. What can transducer elements be made of?

4. What can the backing materials be?

5. What are the problems complicating the beam profiles in contact tests?

6. What are the reasons for the data scattering due to?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The measurements of beam profiles in contact tests.

Unit 11

Focused Practice

I. Answer the following questions:

1. What are perturbations of the magnetic flux in iron and steel due to?

2. What was the chance discovery of Hoke?

3. Who discovered the technique of magnetic particle inspection?

4. When was it discovered?

5. What did DeForest’s work involve?

6. What is the need to use magnetic powders with uniform properties?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The subject of flaw detection.

Unit 12

Focused Practice

I. Answer the following questions:

1. Why have magnetoresistive recording heads heralded a new interest in the basic properties of magnetic materials?

2. Why has there been a keen interest in pushing materials to larger magnetoresistance?

3. How are new multilayer films being developed?

4. What other novel sensors have been proposed?

5. What is a sense current used for?

6. What controls the resolution of the sensor along the track?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Magnetoresistive recording heads.

Unit 13

Grammar: The Gerund

Word List:

1. membrane	мембрана, пленка
2. desalination	опреснение
3. reverse osmosis	обратный осмос (обратная диффузия)
4. quantum leap	количественный скачок
5. trend	направление, тенденция
6. osmotic pressure	осмотическое давление
7. rather than	а не; скорее...чем
8. porous sublayer	пористый подслой
9. in situ	на месте
10. as compared to	по сравнению с
11. tolerance	стойкость, выносливость

Progress in Membrane Science and Technology for Seawater Desalination

Membrane technologies have been incessantly progressing during the past forty years. No limit in the future progress is currently in sight. Contributions to membrane science and technology, upon reaching a critical mass, will result in another quantum leap that is equivalent to the historic announcement of the Loeb-Sourirajan membrane in nineteen sixty. There are some new trends observable in the following four areas: membrane development, membrane characterization, membrane transport and membrane system design. Membrane development deals with recent progresses in the development of reverse osmosis membranes used for desalination.

To increase the pure water recovery by a membrane module from the conventional 40 % to 60 % is a trend observable in seawater desalination technology. Since the osmotic pressure of the retentate will increase from 4.5 to 7.0 MPa when the water recovery increases from 40 to 60 %, the development of a high pressure vessel as well as the development of a membrane that will show little compaction under a high pressure is necessary. Kawada reported recently on the development of a reverse osmosis membrane that was suitable for operation at 9 MPa. He found that membrane compaction took place at the porous sublayer rather than at the skin layer. An attempt was therefore made to reduce the compaction by making a large number of uniform pores of small sizes at the surface of the porous sublayer on which an aromatic polyamide skin layer was coated by in-situ polycondensation.

The stability of the membrane module productivity increased significantly as compared to the conventional seawater desalination membrane.

One of the drawbacks of composite membranes based on aromatic polyamide is poor chlorine tolerance. Many attempts have been made to improve the chlorine resistance of composite membranes by changing the molecular structure of the monomers used for the polymerization. A patent was recently issued on a composite membrane that is chlorine resistant.

Focused Practice

I. Answer the following questions:

1. What new trends are there in membrane technologies?

2. What does membrane development deal with?

3. Where does membrane compaction take place?

4. What was made to reduce the compaction?

5. What is one of the drawbacks of composite membranes?

6. What attempts have been made to improve the chlorine resistance of composite membranes?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: One of the drawbacks of composite membranes.

Unit 14

Grammar: The Passive Voice

Word List:

1. turbulent combustion	турбулентное сгорание
2. chemical reaction rate	скорость химической реакции
3. thin reaction sheets	емкость из тонкостенных листов
4. length scale	линейный масштаб
5. disparity	несоразмерность, несоответствие, различие
6. by and large	вообще говоря
7. flame	пламя; факел пламени
8. with respect to	в отношении, что касается
9. velocity	вектор скорости
10. to exploit	использовать

Asymptotic Methods in Turbulent Combustion

There are a number of different regimes of turbulent combustion, dependent upon the intensity and scales of the turbulence, measured with respect to suitable combustion parameters derived from the chemical reaction rates. In one set of these regimes, combustion occurs in thin reaction sheets, transported and distorted by the turbulence. In these reaction sheet regimes, more than one characteristic length scale is involved in the turbulent combustion; there are short scales associated with the chemical processes and long scales associated with the turbulence. The disparity of scales causes asymptotic methods to be advantageous for studying turbulent combustion in reaction sheet regimes. A significant amount of progress has been made recently by use of asymptotic methods for describing these regimes in both premixed and nonpremixed turbulent combustion. By and large, the objectives have been not to calculate the turbulent reacting flows completely, but rather to relate the properties of interest in these flows to properties of nonreacting turbulent flows. It then becomes possible to use the existing methods of analysis of nonreacting flows to calculate the results of interest for turbulent combustion. The intent of the present paper is to review the recent advances achieved by use of the methods described above and to identify not only what is known but also areas of unknowns for future research. Other reviews covering material of this type have been published.

The techniques employed in analyzing turbulent combustion differ for premixed and nonpremixed systems. This is especially true in various finer details of analyses of reaction sheet regimes. Therefore, it will be convenient here to treat turbulent premixed flames and turbulent diffusion flames separately. Presentations more unified in character may become appropriate in the future since there are a number of similarities, e.g., the reaction sheet aspect itself. However, it seems likely that certain essential differences will remain; burning velocities exist for premixed but not for nonpremixed combustion (at least not in the same sense).

In recent years asymptotic methods have contributed greatly to an improved understanding of turbulent combustion in both premixed and nonpremixed systems. These methods must be incorporated into flowfield calculations before they can be fully exploited.

Focused Practice

I. Answer the following questions:

1. What do different regimes of turbulent combustion depend upon?

2. What are asymptotic methods used for?

3. Why is it convenient to treat turbulent premixed flames and turbulent diffusion flames separately?

4. What presentations may become appropriate in the future?

5. What combustion do burning velocities exist for?

6. When can asymptotic methods be fully exploited?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The reaction sheet regimes.

Unit 15

Focused Practice

I. Answer the following questions:

1. What does the treatment of water by membrane technology imply?

2. What is a survival strategy in oligotrophic systems?

3. What will the organisms do when they colonize the surface?

4. When is the term “biofouling” applied?

5. Why if biofouling the “Achilles heel” of the process in membrane systems?

6. How is the biofouling potential represented?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The vertical transport vector.

Unit 16

Grammar: Modal Verbs

Word List:

1. compatibility	совместимость
2. host	первичный материал, минерал-«хозяин»
3. a solid-state battery	твердотельная батарея
4. a voltage window (a voltage range)	диапазон напряжений
5. overcharge	избыточный заряд
6. availability	наличие
7. unstrained bonds	недеформированные связи (соединения)
8. both....and	как...так и; и...и
9. primarily	в первую очередь
10. until recently	до недавнего времени

What Materials Are Suitable as Polymer Electrolytes?

As the electrolyte must function as both a separator and an electrolyte in a solid-state battery (still seen as the major application for these materials), then a number of properties are critical for its success. The electrolyte must satisfy a minimum of requirements from an electrochemical point of view:

· Conductivity: the electrolyte must have sufficient ionic conductivity to allow a reasonable current density; 10 S/cm would be ideal at room temperature although a lower value may be acceptable (Armand originally quoted 10 S/cm minimum practical value).

· Electrochemical stability: the electrolyte should be electrochemically stable in a voltage window that is at least as wide as the voltage window defined by the electrode reactions (it should preferably be wider, to accommodate overcharge and discharge reactions).

· Compatibility: they must be chemically and electrochemically compatible with electrode materials.

· Thermal stability: electrolytes must have good thermal stability, especially in contact with a lithium electrode.

· Mechanical stability: the mechanical stability becomes important as battery technology moves from laboratory into process development, pilot production and, finally, full, production.

· Availability: raw materials must be readily available and inexpensive. Exotic materials have many uses as model compounds but may be impractical at a production level.

While many electrochemists throughout the 1980s preferred to study simple PEO-based polymer electrolyte systems using phase diagrams as a guide to suitable salt concentrations and temperature ranges, polymer chemists began to design more appropriate electrolyte constituents, primarily polymer hosts. The lain advantage of PEO as a host is it is chemically and electrochemically stable, since it contains only strong unstrained C-О, C-C, and C-H bonds. It is not surprising therefore that alternative host polymers have tended to incorporate ether units. It has perhaps been unfortunate that, with the bulk conductivity as the prime motivator of polymer electrolyte design, the other five factors listed above have not, until relatively recently, had the attention they deserve. As a result, the vast majority of alternative polymer hosts synthesized will have little practical application.

Focused Practice

I. Answer the following questions:

1. What requirements must the electrolyte satisfy from an electrochemical point of view?

2. What must the electrolyte have sufficient ionic conductivity for?

3. Where should the electrolyte be electrochemically stable?

4. Why did polymer chemists begin to design polymer hosts?

5. What tendency do alternative host polymers have?

6. What practical application will alternative polymer hosts synthesized have?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Thermal and mechanical stability of electrolytes.

SECTION II

ELECTRICAL  ENGINEERING
AND  ELECTROMECHANICS

Unit 17

Focused Practice

I. Answer the following questions:

1. What does the structural integrity of turbine disc components
depend on?

2. What knowledge is required to calculate the service life of each component of the turbine disc?

3. What can photoelasticity be used for?

4. Why have techniques that predict the directions of crack growth been developed?

5. Where does crack initiation occur?

6. What is the photoelastic prediction of the fatigue crack path constructed from?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Fatigue cracks in turbine discs.

Unit 18

Grammar: The Passive Voice

Word List:

1. tip seal arrangement	герметичное устройство, кожух
2. forward and rear assemblies	передний и задний блоки (агрегаты)
3. blades	лопатки, лопасти (fixed – неподвижные, moving – движущиеся)
4. bearing housing bearing wall	установочный узел с подшипниками несущая стена
5. casing	кожух, каркас, рама
6. clearance	зазор
7. plenum chamber	нагнетательная камера высокого давления
8. cold setting	холодная обмуровка (на холоде)
9. downstream	нисходящий поток
10. gland	сальник, уплотнитель
11. traverse /traversable probe instruments	зонды (приборы для определения поперечных потоков в лопатках турбины)
12. carrier rings	несущие кольца
13. rack and pinion arrangement	зубчато-реечная передача
14. trailing edge stiffness	жесткость задней кромки
15. split shaft 16. thrust	разъёмный вал осевое давление
17. fitting and removal	сборка и разборка
18. friction and torque load	нагрузка, обусловленная трением и моментом вращения
19. spacing ring	шайба
20. pitch and lean angle	продольный и поперечный крен

The Split Shaft Design

The turbine casing is divided into structurally independent forward and rear assemblies to suit the split shaft design. Each of the two bladed discs is mounted on its own separate cantilevered shaft system in a manner which allows rapid fitting and removal. The first stage diaphragm and rotor are housed in the forward assembly which is bolted onto the inlet plenum chamber. This assembly also carries the second stage diaphragm since the diaphragm glands of both stages seal against the first stage shaft. The rear assembly, which is mounted on its own foundations, carries the bearing housings and tipseal arrangement for the test stage. Thisavoids any problem with setting and maintaining correct radial clearances which might otherwise arise due to the split shaft arrangement. The abutment between the two assemblies lies between the test stage fixed and moving rows and the rear section can slide axially on its mountings to allow variation of the interspace gap and to provide access for traversable probe instruments. Spacing rings areinserted between the casing sections to form the end wall profile.

The rear assembly can also be removed as a unit to improve access during strip and rebuild operations.

Special moulding techniques have been developed to produce low cost plastic fixed blades with steel reinforcements to provide adequate trailing edge stiffness and overall diaphragm strength. Cold setting plastics are also used in the construction of model diaphragms to retain the fixed blades at the precise chosen settings of stagger, pitch and lean angle. After test the diaphragms can be readily dismantled and the blades reused in later test configurations.

Radially adjustable rollers support the test stage diaphragm in order to allow the fixed blades to be indexed past the traverse probe instruments at the moving blade inlet and outlet planes. Traverse probe instruments at the stage inlet plane are held in the rotatable diaphragm and are thus traversed circumferentially through the wakes from the first stage fixed blades. The diaphragm rotational movement is effected through a rack and pinion arrangement.

An air bearing on the downstream face of the diaphragm carrier ring is pressurized during rotation to lift the diaphragm axially against the aerodynamic thrust to reduce friction and torque load.

Focused Practice

I. Answer the following questions:

1. Why is the turbine casing divided into structurally independent forward and rear assemblies?

2. How is each of the two bladed discs mounted?

3. Where are the first stage diaphragm and rotor housed?

4. What does the rear assembly carry?

5. Where does the abutment between the two assemblies lie?

6. What have special moulding techniques been developed for?

7. Why are cold setting plastics used in the construction of model diaphragms?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Forward and rear assemblies.

Unit 19

Focused Practice

I. Answer the following questions:

1. How many losses are present when the motor is running idle?

2. What are these losses?

3. What is “copper loss”?

4. What does taking idle readings of current and power as the voltage is varied permit?

5. Why will the core loss from an idle test be quite the same at full load?

6. (What)When can the slight difference become important?

7. Why have separate tests for core loss become popular in recent years?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Motor losses

Unit 20

Grammar: The Infinitive. The Infinitive Constructions.
The Passive Voice

Word List:

1. hydraulic system design	проектирование гидравлической системы
2. computational techniques	вычислительные методы/приемы
3. pneumatic system	пневматическая система
4. fluid power	гидравлическая мощность
5. design procedures	методы  конструирования
6. feasible circuits	выполнимые, возможные схемы
7. servohydraulic circuits	сервогидравлические сети
8. selection database	база отбора данных
9. load attributes	характеристики нагрузки
10. hydraulic power unit	гидравлический энергоблок
11. KEOHPS	Knowledge Engineering on Hydraulic and Pneumatic Systems
12. tool	инструмент, средство
13. browser	браузер, просмотр
14. fire and mining	Пожаро- и взрывоопасность

Expert Systems for Fluid Power

The application of expert systems to hydraulic system design has been thoroughly studied. Hydraulic systems are made up primarily of pre-engineered components that each has a specific function. Thus, system functionality can bebroken down into its basic units. Considering that fluid power is more than a billion-dollar industry, a computational system for fluid power should carry strong market potential.

Design procedures for hydraulic systems have been well established, primarily in technical books and manufacturers’ literature. These design techniques are of paramount importance for developing expert systems, and the component-oriented nature of fluid power systems is an ideal fit. Many engineers and designers involved in fluid power technology have a background in machine design, but lack a command of computational techniques. This makes it difficult for them to realize the value of expert systems without having witnessed the demonstration of a prototype. The prototype has proven to be sufficiently useful to raise interest from a number of fluid power designers to collaborate on its enhancement.

A technology-based enterprise has been established in Florianopolis, SC, Brazil, to develop computational systems for fluid power. The enterprise is known as KEOHPS. The goal of KEOHPS is to develop computational solutions using artificial intelligence to design hydraulic and pneumatic systems. A key element of this program is that the systems are intended for both national and international markets.

The prototype is a result of an international research project involving experts from Brazil, western Europe, and the U.S. In its present form, it has the capability to:

· prompt the user to respond interactively to determine system requirements without requiring extensive knowledge of hydraulics;

· automatically generate a set of feasible circuits - based on well-proven principles of circuit design - for consideration by the designer;

· allow preliminary ranking of alternative solutions from general attributes;

· allow altering the hydraulic power unit (HPU) model and redefining component model lists;

· calculate the HPU demand based on load attributes (force, speed, torque, etc.);

· handle servohydraulic circuits;

· generate topological dynamic simulation models tailored to a specific simulation package;

· display circuit schematics and component specifications through automatically generated pages that can be viewed through an Internet browser, and

· offer a fluid selection database through which the user can search via keyword combinations, such as fire and mining.

A comprehensive prototype model was developedto demonstrate the system to as many experts as possible. The prototype was presented to individuals in the fluid power industry through visits to component manufacturers and participation at conferences and technical trade shows. Based on observations during its validation by fourth-year engineering students, the system also holds potential as an educational tool.

Focused Practice

I. Answer the following questions:

1. What are hydraulic systems made up primarily of?

2. Why is a computational system for fluid power of paramount importance?

3. Where has a technology-based enterprise been established?

4. What is the name of the enterprise and its goal?

5. What is a key element of this program?

6. What makes this research project international?

7. What does the prototype have the capability to do?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Hydraulic systems.

Unit 21

Focused Practice

I. Answer the following questions:

1. What does output from the prototype pay special attention to?

2. Where are alternative HPUs described?

3. What does the prototype do once a selection of design options is made?

4. How many choices for actuation circuits does the program provide? 

5. When does the prototype establish all ranking systems as guidelines for the user?

6. How can users address the design problem?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The ability to automatically size the circuits.

Unit 22

Grammar: Word-building. The Conjunctional
and Prepositional Phrases

Word List:

1. exhaust hood	выхлопной патрубок, вытяжной шкаф
2. transonic flow	поток, проходящий со скоростью звука
3. domain multi-domain	область; многоступенчатый
4. complexity	запутанность, сложность
5. diffuser	распылитель, рассеиватель
6. boundary conditions	граничные условия
7. three-dimensional	трехмерный
8. throughflow	прямой, сквозной поток
9. planes	решетки, подложки под граничным слоем
10. architecture	сеть, структура, строение
11. aerodynamics	аэродинамика
12. finite volume	ограниченный объём
13. mechanical stress	механическое напряжение

The Calculation of a Last Stage Low
Pressure Steam Turbine and Exhaust Hood Flow

In large nuclear steam turbines, the last stage and exhaust hood are very important. Indeed, their high contribution to the total turbine output as well as the critical last stage operating conditions (transonic flow, wet steam, high mechanical stresses, ...) have led to a large number of various studies. Therefore, a greater attention is being devoted to the diffuser designed to recover kinetic energy and to increase last stage efficiency. Moreover, a reduction of diffuser length helps to reduce the shaft length which is always very interesting from the economic point of view.

Obviously, the calculation of a last stage low pressure steam turbine and exhaust hood flow is difficult due to the complexity of three dimensional flow in addition to the multi-domain. Indeed, it is quite impossible to determine appropriate boundary conditions for a local calculation without coupling techniques. A way to solve this problem is to perform a throughflow calculation of the whole cylinder. However, this method is not very useful for the complex low pressure last stage flow and quite impossible for the three-dimensional exhaust hood flow. Another way consists of simultaneously solving the aerodynamic flow problem in the stator, in the rotor and in the exhaust hood. Of course, this method seems very complex and expensive. However, in relation to the modern computers this method is nowadays realistic and very promising in relation to the new parallel architecturecomputers. The last stage flow is always unsteady because of the rotor. The principal assumption is that the flow is steady relative to each domain individually and that each domain can communicate via mixing planes These introduce circumferential averaging of the flow properties, but preserve quite general radial variations.

Focused Practice

I. Answer the following questions:

1. What has led to a large number of various studies?

2. What is a greater attention being devoted to?

3. Why is a reduction of the shaft length very interesting?

4. Why is the calculation of a last stage low pressure steam turbine and exhaust hood flow difficult?

5. What is a way to solve the problem?

6. What does another way consist of?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: Specification of calculatingthe the above equipment.

Unit 23

Focused Practice

I. Answer the following questions:

1. Where have the measurements been carried out?

2. What can you say about the rotor blades of the first stage and the turisted rotor blades of the second and third stages?

3. What is the numerical method based on?

4. How is discretization in time performed?

5. What is a multiblock method used for?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The numerical methods and the Runge-Kutta scheme.

Unit 24

Focused Practice

I. Answer the following questions:

1. What word-combinations do the letters CAD and BPM stand for?

2. What are large size reductions due to?

3. How can the improvements be gained?

4. How has the thermal performance of a new motor design traditionally been estimated?

5. What is the problem with traditional design methods?

6. What can one of the thermal modules of a new available motor design package be used for?

II. Analyse the grammar structures underlined in the above text.

III. Speak on: The revolution in compact BMP motors.

Unit 25

Grammar: The Infinitive

Word List:

1. micro-electro-mechanical systems (MEMS)	электромеханические микросистемы
2. the microbearing device	устройство, опирающееся на микроподшипники
3. power MEMS applications	устройства MEMS большой мощности
4. rig	оснастка
5. microbiaricated rotor	микроротор
6. LIGA=lithography	литография, нанесение металлического слоя
7. induced stresses	обусловленные воздействия
8. rpm=revolutions per minute	об/мин
9. two orders	два порядка, т.е. в 100 раз
10. aircraft propulsion	двигатель летательного аппарата
11. circumferential tip speed	окружная скорость
12. pin bearing	шарнирно-неподвижная опора
13. turbomachinery	турбины
14. viscous drag	вязкостное торможение

Demonstration of a Microfabricated High-Speed Turbine Supported
on Gas Bearings

To achieve high power and efficiency from a rotating device, high circumferential tip speed is a necessity. Conventional scale turbomachinery typically run with tip speeds of order 500 m/s, enabling high-power density applications such as gas turbines for aircraft propulsion and power generation. In order to achieve high levels of power density, microfabricated rotors will need to run at comparable tip speeds. Typical rotating micromachines, such as gears and micromotors, are formed either by surface micromachining or LIGA, supported by solid contact on a pin bearing, and entrained by electrical or contact forces acting on the edges of the rotor. These micro-rotors have reached of order 2 m/s tip speed, which is two orders of magnitude lower than desired for Power MEMS applications.

An effort has been undertaken to develop high-speed rotating devices to enable high-power density MEMS. A single-crystal silicon air turbine supported on gas lubricated bearings has been operated in a controlled and sustained manner at rotational speeds greater than 1 million rpm and power levels approaching 5 W. The device is a second-generation version of the microbearing rig first reported in 1999, and is the first micromachine tooperate at circumferential tip speeds of hundreds of meters per second, comparable to conventional scale turbomachinery. To achieve this level of peripheral speed, microfabricated rotors must withstand large induced stresses, need a sufficient power source to drive them, and require stable, low friction bearings for support. The successful operation of the microbearing device motivates the use of this technology for high-power density MEMS.

The turbine was designed to provide sufficient power to overcome the viscous drag in the bearings and on the back side of the rotor. While viscous drag is relatively large in microsystems due to the small length scale, it is still quite small compared to the capabilities of high-speed turbomachinery. The turbine for the microbearing device had to be intentionally designed to match the relatively low power requirements of the viscous drag. Alternative turbine designs, compatible with the current process and geometric constraints, that produce tens of watts of power (beyond the drag requirements) have been designed for Power MEMS applications.

Focused Practice

I. Answer the following questions:

1. What is necessary to achieve high power and efficiency from a rotating device?

2. How are typical rotating micromachines formed?

3. What effort was undertaken?

4. How has a single-crystal silicon air turbine supported on gas lubricated bearings been operated?

5. Was the operation of the microbearing device successful?

6. What turbine designs have been designed for Power MEMS ap