Twin heads are better than one



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ЗНАЕТЕ ЛИ ВЫ?

Twin heads are better than one



Today CNC turning machines are available in a confusion of spindle configurations, making life difficult for anyone looking for a machine to do a given type or range of work. While the single spindle machine is still the basic tool, there have to be good reasons for not choosing a machine with a second spindle.

The overriding benefit of the second spindle is it opens up the way for more complex parts to be finished on one machine, using one program and setup. This has made such machines very popular, in particular the second-operation or sub-spindle type machine intended for secondary and back-end work.

The most established type of twin-spindle machine is the front-loader with its two identical spindles mounted side by side on parallel axes. Most common are those with horizontal spindles but twin spindle vertical machines are available, offering the benefits of ease of loading and good support for heavy work.

Front facing horizontal spindle machines have proved most versatile where an overhead gantry is used to move workpieces between left- and right-hand spindles. In addition to providing automatic and programmable transfer, the gantry enables work to be turned round or over as it is moved between stations.

An example of what is possible with this configuration is the Takamaz CNC twin-spindle lathe. Its right- and left-hand spindles have independent machining capabilities that permits simultaneous machining. This enables front and rear of a part to be machined at the same time, using the controlled axes of the six- or ten-station (depending on the model) tool turret

On this type of machine work is transferred into and out of the stations and between them using an overhead servo loader. Three types of spindle indexing are available for these machines - mechanical, electrical and c-axis controlled indexing - which, in conjunction with power tooling, enable a range of compound machining operations to be carried out.

A big advantage offered by vertical twin-spindle machines of this type is the ease with which workpieces can be loaded and supported. For larger workpieces, it is possible to fit semiautomatic work-loading equipment. Alternatively, a gantry or floor-standing robot can be used for parts up to 20 kg.

 

1. Выпишите из текста причастия I в функции обстоятельства и переведите их вместе с относящимися к ним словами.

2. Выпишите из первого абзаца конструкцию There+be, обратите внимание на присутствие глагола to have в этой конструкции, определите его функцию, переведите эту конструкцию.

3. Выпишите из второго абзаца инфинитив, укажите его функцию и переведите вместе с относящимися к нему словами.

4. Найдите во втором абзаце придаточное предложение сказуемое, проанализируйте его и переведите его вместе с подлежащим главного предложения.

5. Найдите в тексте слово-заместитель ранее употребленного существительного и переведите его, определив заменяемое им слово.

6. Выпишите из третьего абзаца причастие I, определите его функцию и переведите предложение, обращая внимание на порядок слов при переводе.

7. Найдите в тексте инфинитивные обороты и переведите их.

8. Выпишите из пятого абзаца сложноподчиненные предложения, определите вид придаточных предложений и переведите их вместе со словами, к которым они относятся.

9. Найдите в тексте безличное предложение и переведите его.

10. Переведите текст с учетом выполненных заданий.

 

Text 15

Renault's Euro 3 engine

General engine features

The new engine is an inline six-cylinder unit with a 123-mm (4.84-in) boreand a 156-mm (6.14-in) stroke for a total capacity of 11.1 L. All engine components were designed and developed using computer-aided design (CAD) connected to 3-D calculations in mechanical, thermomechanical, fluid flow, injection, and combustion areas.

A one-piece cylinder head contributes to the engine block stiffness, in addition to a ladder frame crankcase. To provide a central location for the injectors and optimal engine air breathing, the cylinder head has four valves per cylinder and 20° skewed, cross-flow intake and exhaust ports. As an option, an engine-brake can be mounted above the cylinder head to offer high braking power. The camshaft has a lateral position in the block, and roller tappets are used. The articulated piston has a forged steel crown and a cast aluminum skirt. Special attention was paid to piston-ring and -sleeve optimization for low oil consumption, contributing to a very low soluble oil fraction in the exhaust under all conditions.

A key feature of the engine is the fully electronic-controlled common-rail injection system. The system allows the control of pressure independently of engine speed and load, high flexibility of multiple injections for low emissions and noise, and continuous high injection pressure for reduced particulate emissions. Special care was taken to prevent unexpected engine stall or defective sealing and to allow a limp-home mode. The filtration and low-pressure system were entirely redesigned to maximize the benefits of this new injection system. The system can supply up to four injections to a cylinder per cycle; this can be a combination of pilots, posts, and main injections.

The injectors, centered in the four-valve combustion chamber, have screwed electrical connections for long life, they being supplied with fuel through connectors that are also screwed into the cylinder head. Each injector has eight holes, a mini sac-type tip, and an optimized needle seat for long-term fueling rate stability.

The rail assembly acts like an electrical circuit capacitor, separating the pump from the injectors. The high volume of fuel contained in the rail and the high-pressure tubes, compared to the maximum injected quantity, maintains a constant pressure for optimized combustion. The rail has a pressure sensor, a flow limiter for each injector, and a pressure limiter.

 

1. Выпишите из текста сказуемые в страдательном залоге и переведите их вместе с подлежащими.

2. Выпишите из первого абзаца причастие I, определите его функцию и переведите вместе с относящимися к нему словами.

3. Выпишите из текста все инфинитивы в функции обстоятельства и переведите вместе с относящимися к ним словами.

4. Найдите во втором абзаце предложение с as, определите его функцию и переведите вместе с относящимися к нему словами.

5. Найдите в тексте независимый причастный оборот и переведите его.

6. Выпишите из предпоследнего предложения текста глагольные формы с окончанием –ed, укажите их функции и переведите их вместе с относящимися к ним словами.

7. Выпишите из текста именные группы и переведите их.

8. Переведите текст с учетом выполненных заданий.

Text 16

Renault's Euro 3 engine (continued)

The high-pressure pump is lubricated by engine oil and driven at half crankshaft speed. It has two inline high-pressure cylinders that can generate a constant pressure of 140 MPa (20 ksi) in the rail with a displacement of 681 mm3/stroke (0.042 in3/stroke). The pump camshaft has two cams with three lobes per cam. After each injection, the pump delivers the needed quantity for keeping pressure constant in the rail. For the two pump cylinders, the fuel metering unit (FMU) has two separate circuits and two solenoid valves that provide control of the rail pressure with one pump element in case of failure of the second one.

The electronic control unit (ECU) is mounted on the engine and cooled by fuel through a cooling plate. This plate not only cools the ECU, but also reduces the vibration it experiences by using dampers between the cooling plate and engine block to make sure its wires have the same vibration mode as its connector.

Depending on the difference between the pressure in the rail and the pressure threshold, the ECU energizes the FMU's solenoid valves to adjust the fuel quantity to be pressurized by the pump elements. This principle allows only the quantity needed to be pressurized, and it does not require the full use of pump capacity. This, in turn, reduces pump torque while keeping loads more uniform on the pump drive and reducing temperature of the back flow fuel.

Since common-rail injection introduces gallery pressure as a new degree of freedom, a new method was developed to tune the parameters of the pressure regulation – in steady and transient states - by using an electric test bench, engine test cells, and test vehicles. The final optimized fuel maps are said to allow excellent driveability during load pickup and instantaneous cold starting without any white smoke.

In addition to ECU monitoring and failure detection, pressure and flow limiters in the rail provide an improved level of safetyover all other existing systems. Blockage ofthe flow limiter prevents damage to the cylinder head by restricting the fuel quantity injected. Also, should a part or seal break in a cylinder, the flow limiter blocks fuel to that cylinder, and the engine continues running on five cylinders.

 

1. Найдите в первом абзаце сложноподчиненные предложения. Укажите их количество, а также союзы (союзные слова), которые присоединяют придаточные предложения к главным.

2. Найдите в тексте придаточное бессоюзное определительное предложение и переведите его вместе с определяемым существительным.

3. Найдите в тексте придаточное бессоюзное дополнительное предложение и переведите его вместе с тем глаголом, к которому оно относится.

4. Выпишите из текста инфинитив в функции определения, переведите его вместе с относящимися к нему словами.

5. Выпишите из текста инфинитивные обороты и переведите их.

6. Выпишите из текста герундии в функции обстоятельства и переведите их вместе с относящимися к ним словами.

7. Выпишите из текста причастия I в функции обстоятельства и переведите их вместе с относящимися к ним словами.

8. Найдите в последнем абзаце бессоюзное условное предложение и переведите его, предварительно определив тип условного предложения.

9. Переведите текст с учетом выполненных заданий.

 

Text 17

Fuel Cell Technology

There can be few events in the motoring calendar this century as significant as the launch of the DaimlerChrysler Necar 4 at the Ronald Reagan International Trade Centre in Washington. Billed as the world's first practical fuel cell vehicle, Necar 4 is the latest in a long line of Necar (New Electric Car) and Nebus projects aimed at bringing proton exchange membrane fuel cell technology to the masses by 2004, thus creating a whole new industry and solving the world's vehicle emissions problems in one fell swoop.

Necar 4 is based on the Mercedes A-class, not specifically designed for fuel cell use, but was originally planned with the double-skin floor in which the system is installed.

The earliest version, Necar1, built in1994, was a Mercedes van filled entirely with a fledglingfuel cell system, leaving just about enoughroom for a passenger. GM'sZafiraprototypesare similar and mostly filled with methanol and gasoline reforming systems. Now, Necar 4, in which the fuel cell is fed by compressed hydrogen, is a full five-seater.

The fuel cell is produced by DBB Fuel Cell Engines, a company formed in partnership between DaimlerChrysler, Ford and Ballard Power Systems of Canada. Each cell comprises a pair of porous electrodes sandwiching the platinum-coated membrane with air supplied on one side and hydrogen on the other. Protons from the hydrogen migrate through the membrane to react with oxygen in the air producing water and creating a difference in the voltage at the electrodes which is harnessed to create an electric current.

The system produces 76 ps (55 kW) and undisclosed torque, giving Necar 4 a top speed of 145 km/h and range of 450 km. Fuel consumption is equivalent to 3.2 I/100 km (88 mpg) in this, the compressed hydrogen version, and 3.6 I/100 km (78 mpg) using methanol. The system takes a short time to start from "key-on", but soon settles down to a quiet hum as the compressor feeds hydrogen to one side of each cell and air to the other. The stack contains 400 cells capable of producing between 1 and 2 V each with an energy density of 1 amp/cm2. A realistic maximum is 750 V and since 250V is required to drive the powertrain on demand, there is a comfortable margin.

 

1. Найдите в тексте предложения с конструкцией There+beи переведите эти конструкции.

2. Выпишите из текста герундии, укажите их функции и переведите вместе с относящимися к ним словами.

3. Найдите в тексте случаи употребления as, определите их функции и переведите вместе с относящимися к ним словами.

4. Найдите в первом абзаце предложение с инверсией и переведите его, обращая внимание на порядок слов при переводе.

5. Выпишите из текста причастия I в функции обстоятельства и переведите их вместе с относящимися к ним словами.

6. Выпишите из текста все сказуемые в страдательном залоге с последующим дополнением с предлогом by и переведите их, используя два варианта перевода.

7. Выпишите их текста именные группы и переведите их.

8. Переведите текст с учетом выполненных заданий.

Text 18

Local Area Networks (LANs)

Distributed Processing and Networks

Although it only is with the arrival of the microcomputer that companies have been able to implement LANs, the concept itself is not new. It represents a logical development and evolution of computer technology. The first computers in the 1950s were mainframes. Large, expensive, and reserved for very few select users, these monsters occupied entire buildings.

These first computers were not designed for online response to a user's commands. They used a batch approach. Users submitted coded cards containing their data and program commands. Computer professionals fed these cards into the computer and usually sent the printed results to the users the next day. A miscoded card usually meant that the user would have to resubmit the entire program the following day.

At this time there was little need to share computer resources such as printers and modems. Computers were so few (and so costly) that the average office could not afford one. One solution to this expense problem was time-sharing. During the 1960s it became possible for an office to use a "dumb" terminal, modem, and card reader to connect through a telephone line with a mainframe computer. By leasing (or sharing) time on this computer, the user was able to enjoy the benefits of computerization without massive capital expenditure.

The major problem with time-sharing was the slowness of sending information over telephone lines. During the early 1970s, the production of the minicomputer (so called because it was smaller than a mainframe, though it worked in much the same way) avoided this problem. Because of the dramatic drop in prices, departments were able to have their own computers.

All a new user needed to become operational was a terminal — and the cabling between it and the minicomputer. As Figure 1.1 illustrates, several users were able to use the same computer, and much higher speeds were possible than under time-sharing. The concept of distributing computer resources throughout a company — by providing different departments with their own computers, rather than using one central computer for everybody — became known as distributed processing. But even though several departments in a company had their own minicomputers, providing communications among these computers still posed a problem. Therefore, companies began cabling these computers together and writing software necessary for the units to communicate with each other.

As microcomputers became much more powerful (and much less expensive) during the 1980s, companies began to take a second look at their minicomputers. Costing hundreds of thousands of dollars, these larger computers were not able to run the newer, more sophisticated business programs that were coming out for IBM PCs and compatibles.

 

FIGURE 1.1.

Distributed processing with a minicomputer.

 

By the mid-1980s, thousands of office workers began bringing their own personal computers to work in order to use the new business software written for PCs. As employees began exchanging floppy disks and keeping their own databases, companies began to have serious problems with maintaining the integrity of their data. LANs offered a solution to such problems.

 

1. Найдите в тексте предложение с усилительной конструкцией и переведите его.

2. Выпишите из текста предложение с глаголом to have в качестве модального глагола и переведите это предложение.

3. Найдите в тексте предложение с конструкцией There + beи переведите его.

4. Найдите в тексте безличное предложение и переведите его.

5. Выпишите из текста герундии в функции обстоятельства и переведите их вместе с относящимися к ним словами.

6. Найдите в тексте придаточное бессоюзное определительное предложение и переведите его вместе с определяемым существительным.

7. Выпишите из последних трех абзацев все союзы и союзные слова, присоединяющие придаточные предложения к главным, и переведите их.

8. Выпишите из предпоследнего абзаца причастие I, определите его функцию и переведите вместе с относящимися к нему словами.

9. Выпишите из первого предложения последнего абзаца инфинитив, укажите его функцию и переведите вместе с относящимися к нему словами.

10. Переведите текст с учетом выполненных заданий.

 

Text 19

What Is a LAN? (continued)

Distributed processing, taken to its logical conclusion, came to mean linking micro-computers together so that they could share information and peripherals. This was the idea behind the first local area networks. The broadest possible definition of a LAN is: a communication network used by a single organization over a limited distance which permits users to share information and resources.

This text surveys the different types of physical configurations possible for a LAN. Whether PCs are arranged in the form of a star, a ring, or even a straight line, the speed of the network depends on the media used to connect the units. The text also examines the different types of cabling available for LANs and their effect on network performance.

The first LANs were relatively primitive. Faced with a serious shortage of software designed for more than one user, these first LANs used file-locking, which allowed only one user at a time to use a program. Gradually, however, the software industry has become more sophisticated; today's LANs offer powerful, complex accounting and productivity programs to several users at the same time (record-locking).

Widget's LAN

Now we'll take a look at a hypothetical company which has linked its PCs together to form a LAN with which to share information and printers.

Widget's LAN enables company employees to share data and peripherals (hard disk drives, printers, plotters, and so on). The Widget network enables dozens of workstations to share a variety of printers — including laser, inkjet, and dot-matrix — rather than each PC workstation's having its own dot-matrix printer. Instead of buying dozens of copies of a word processing program, Widget buys a special network version of the program. This enables dozens of network users to share the program—and, more importantly, one another's documents.

A single computer's hard disk serves as the storage area for a network file server. It acts very much like a waiter in a busy restaurant, serving up the items requested by the customers. Widget can keep dozens of varying standard contracts on its network file server; individual workstations can load these documents, make whatever changes are necessary to individualize the contracts, and then save them under appropriate names. The cost savings from these and other communal uses are impressive. A file server should be dedicated to this function and not used for any other purpose to prevent degradation in a network's performance.

 

1. Выпишите из первого абзаца слова с окончанием –ing, определите, какой глагольной формой они являются, а также их функции и переведите их вместе с относящимися к ним словами.

2. Выпишите из текста инфинитивные обороты, определите их вид и переведите.

3. Выпишите из второго абзаца сложноподчиненное предложение и переведите его.

4. Выпишите из третьего абзаца причастие II в функции обстоятельства и переведите его вместе с относящимися к нему словами.

5. Найдите в тексте случаи употребления слова which, определите его функции и переведите вместе с относящимися к нему словами.

6. Выпишите из предпоследнего абзаца предложение с герундиальным комплексом (сложным герундиальным оборотом) и переведите это предложение.

7. Найдите в пятом абзаце составной предлог и переведите его вместе с относящимися к нему словами.

8. Переведите текст с учетом выполненных заданий.

 

Text 20

A Multimedia Synchronization Model Based on Timed Petri Net

Advanced multimedia systems are characterized by the integrated computer-controlled generation, storage, communication, manipulation and presentation of independent discrete (i.e., time independent, like text and graphics) and continuous (i.e., time dependent, like audio and video) media data. Multimedia presentations involve the integration and display of a variety of data types in the form of both static and continuous media. The introduction of continuous media brings with it certain time-related constraints that must be considered at presentation time.

The word synchronization refers to time. Synchronization in multimedia systems refers to temporal relations between media objects in a multimedia system. Researchers have addressed multimedia synchronization from various perspectives. The major issues include how to specify and how to implement synchronization. Especially in the specification area a variety of techniques have been published and implemented. There are hierarchical models, reference point models and timed Petri nets models to specify multimedia synchronization.

Petri net is a kind of system description and analysis tool, and well known for its ability to model concurrent and sequential activities. Since the concept of Petri net was first introduced by D. C. A. Petri in 1962, the Petri Net theory has developed very rapidly in Europe and America and found its wide application in computer science and other fields. The Petri net is defined as a bipartite, directed graph N={T,P,A} where T, P and A represent a set of transitions (bars), a set of places (circles), and a set of directed arcs, respectively. A marked Petri net Nm={T,P,A,M} includes a marking M which assigns tokens (dots) to each place in the net. For simple Petri nets, firing of a transition is assumed to be an instantaneous event. To represent the concept of nonzero time expenditure in the Petri net, extensions of the original model are required. A class of enhanced Petri net models has been developed which assign a firing duration to each transition. These models are generally called timed Petri net models, and map well to Markov performance analysis.

Thomas D. C. Little and Arif Ghafoor suggested a synchronization and storage model for multimedia objects, which is called Object Composition Petri Net (OCPN) and is mainly based on timed Petri net and temporal interval logic. The basic idea is to represent various components of multimedia objects as places and describe their inter-relationships in the form of transitions. While the concept of instantaneous firing of transition is preserved, a non-negative time parameter is assigned to each place in the net. The authors discussed the reachability, liveness, boundedness, conservation properties of OCPN, and presented the hierarchical storage model and corresponding object retrieval and presentation algorithms. This model has been shown to be quite efficient for specifying multimedia synchronization requirement.

But several issues are not addressed by the OCPN model, one of which is that the user interaction is not well described by the OCPN model. When the user is allowed to interact freely with the presentation, some new synchronization problems may arise. In the presentations involving continuous media, there may be need for synchronization when the user requests for some special effects such as pause and user skips. So we augment the OCPN model in order to deal with the user interaction.

 

1. Найдите в тексте предложение с конструкцией There + be и переведите его.

2. Найдите в тексте инфинитив в функции определения и переведите его вместе с относящимися к нему словами.

3. Выпишите из текста инфинитивные обороты, определите их вид и переведите вместе с относящимися к ним словами.

4. Выпишите из текста инфинитивы в функции обстоятельства и переведите вместе с относящимися к ним словами.

5. Выпишите из третьего абзаца сложное предложение, в котором придаточное определительное предложение, относящееся к подлежащему главного предложения, стоит за сказуемым. Переведите это предложение.

6. Выпишите из третьего и четвертого абзацев союзы и союзные слова, присоединяющие придаточные предложения к главным, переведите эти союзы и союзные слова.

7. Выпишите из текста предложения с глаголом to be в качестве связки в составных именных сказуемых. Укажите, чем выражена именная часть в каждом случае. Переведите эти предложения.

8. Переведите текст с учетом выполненных заданий.

 

Text 21

Laser microscopy open a new dimension

Confocal microscopes

In contrast to conventional microscopes that image only in a single focal plane, confocal laser-scanning microscopes (CLSMs) allow sharp 3-D imaging of objects. In such devices, light fromtea laser, which is first focused by a lens, passes through a pinhole aperture before being focused on the specimen. Light from the specimen, either reflected or fluorescence, then passes through the same focusing lens, which acts as both objective and condenser. A beamsplitter diverts this light to another pinhole aperture. The light passing through the second pinhole is then converted to an electrical signal by a photomultiplier tube (PMT).

The confocal system allows only light from the focal plane to pass through because the pinhole apertures block light above or below that plane. This is in contrast to a conventional microscope that allows out-of-focus images from off-focal-plane layers to be seen.

To produce a 3-D image with the confocal system, the device is scanned over the entire specimen at a fixed height to provide a single-layer image; scanning is then repeated after a vertical shift as small as 50 nm. Multiple-layer scans are combined by a computer into a single 3-D image that can be viewed several ways.

Such confocal microscopes have found applications in biological research and medical diagnostics. For example, because human skin is translucent, living skin can be imaged in three dimensions, allowing fast diagnosis of a variety of ailments.

To prevent blurring due to movements by the patient or blood flow, the confocal scanner uses a rotating polygonal mirror for the scans and takes 30 optical sections per second to rapidly build the 3-D image. The light source is a krypton/argon laser emitting at 488, 568, and 647 nm. Both reflected light and fluorescence data are collected simultaneously, with a dichroic filter separating the two. It takes about 10s for a complete in-depth scan. Data processing on a workstation consumes another 5 min.

The researchers found that the blue 488-nm line gave the sharpest images, with resolutions in the area of 1 μm.

Another major application is materials inspection. With the production of increasingly microscopic parts, 3-D inspection is an essential step in checking dimensions. Similarly, confocal imaging techniques can measure the depth and shape of drilled holes or check the texture of fabric for imperfections.

 

1. Выпишите из первого абзаца герундий в функции обстоятельства и переведите вместе с относящимися к нему словами.

2. Найдите в тексте инфинитивные обороты и переведите их.

3. Найдите в тексте независимый причастный оборот и переведите его.

4. Найдите в пятом абзаце герундий в функции подлежащего и переведите все предложение.

5. Найдите в тексте безличное предложение и переведите его.

6. Выпишите из текста все инфинитивы в функции обстоятельства и переведите их вместе с относящимися к ним словами.

7. Выпишите из текста союзы и союзные слова, присоединяющие придаточные предложения к главным, и переведите их.

8. Переведите текст с учетом выполненных заданий.

 

Text 22

Laser microscopy open a new dimension (continued)

Theta microscopy

A research team at the European Molecular Biology Laboratory (Heidelberg, Germany) is developing a modification of confocal microscopes called a single-lens theta microscope. In this device, the illuminating beam is no longer along the optical axis, but instead pointed at right angles to that axis. While an ellipsoidal region along the axis is detected and another ellipsoidal region across the axis is illuminated, only a smaller spherical region where the ellipsoids overlap is both illuminated and detected. This is the data that contributes to the output signal. In this case, the vertical resolution drops to the same level as the horizontal resolution.

The illumination beam passing through the illumination pinhole is deflected at a dichroic mirror and focused onto a focal point above the surface of a plane mirror. The fluorescent beam, which is detected perpendicularly to the illumination axis via an oblique mirror, passes the dichroic deflector and is focused into the detection pinhole with the subsequent detection optics. The scattered or fluorescent light emerging horizontally is reflected by a prism up the optical axis to the detector, illumination and detection occurring at right angles.

Monitoring molecules in 3-D

Confocal and near-field microscopy can be combined to allow the imaging of individual molecules in three dimensions. In near-field microscopy, the resolution can be made significantly smaller than a wavelength of light by locating the specimen in the near field of a tiny aperture. Researchers at the University of Amsterdam and the University of Leiden use a selective spectroscopic method to marry confocal and near-field techniques.

The key is the excitation of individual molecules one by one in a sample. The scientists tune a single-mode dye laser to the fluorescent excitation frequency of the test pentacene molecules. The actual frequency an individual molecule absorbs is affected by its immediate environment, so no two molecules in the sample region (which is about 3 μm on a side) have identical excitation frequencies. As the frequency of the dye laser is scanned, the molecules emit light one by one.

Scientists determine the location of each molecule within the volume defined by the focal region of the confocal microscope by calculating the centroid of the light detected through the microscope. While the diameter of the light distribution is determined by the wavelength of light used, the centroid that indicates the position of the molecular point source can be determined to a far higher accuracy. In this way, the technique can produce vertical accuracy of 120 nm and horizontal accuracy of 50 nm.

 

1. Выпишите из текста именные группы и переведите их.

2. Выпишите из текста сказуемые в страдательном залоге, имеющие в своем составе модальный глагол, и переведите их вместе с подлежащими.

3. Выпишите из текста сказуемые в страдательном залоге с последующим дополнением с предлогом by и переведите их вместе с подлежащим.

4. Найдите в тексте придаточное бессоюзное определительное предложение и переведите его вместе с определяемым существительным.

5. Выпишите из текста союзные слова, присоединяющие придаточные определительные предложения к главным, и переведите их.

6. Выпишите из текста союзы, присоединяющие придаточные обстоятельственные предложения к главным, и переведите их.

7. Найдите в тексте независимый причастный оборот и переведите его.

8. Переведите текст с учетом выполненных заданий.

 

Text 23

Industry and Environment

Air pollution

The main air quality issue is the dust produced by the working of open pits and by crushing and grinding operations. Dust can also be given off by tailings dams. Workers and nearby communities can be affected by dust in the atmosphere. In addition, particle fall-out around mine sites can contaminate soils and water and damage vegetation.

Mines are also sources of greenhouse gas emissions. CO2 is produced by energy use and methane is sometimes released from underground operations, especially in coal mines. In the past, some deep mines used ozone-depleting CFCs in refrigeration systems. This practice has now largely ceased.

Smelting (the process in which ore is heated for the purpose of separating it from the gangue) produces very large amounts of air pollutants. World-wide, the smelting of copper and other non-ferrous metals releases an estimated 6 million tonnes of sulphur dioxide (SO2) into the atmosphere each year – 8 per cent of total worldwide emissions. Non-ferrous smelters also emit large quantities of arsenic, lead, cadmium and other heavy metals except where highly efficient pollution control equipment is used. Smelters may also be regional pollution "hot spots", whose emissions cause severe local environmental damage as well as contributing to more distant or global phenomena such as acid rain and climate change.

 

Water pollution

Potential sources of water pollution from mining include drainage from surface and underground mines, wastewater from beneficiation, and surface run-off. A particular problem is acid mine drainage. Many mining operations, especially those extracting ores that contain sulphides, such as nickel, copper, iron, zinc, cadmium, lead and coal (if pyrites are present), may produce acidic and metal-bearing solutions resulting from the natural oxidation of the sulphides through exposure to air and water. The combination of acids and metals can have severe effects on the ecology of local watercourses, and the metals can enter and bioaccumulate up the food chain. Acid mine water can be a problem for drainage from both underground and surface workings, as well as drainage from waste rock stock piles and concentrator tailings deposits. It can occur while the mine is operating and even long after its closure, unless specific measures are taken.

Mineral separation processes that make use of dangerous and toxic chemicals such as sulphuric acid or cyanide (e.g. leaching) or organic reagents (e.g. flotation) can be serious sources of contamination if appropriate control systems are not in place. Furthermore, much mine wastewater contains large amounts of suspended solids (ranging from colloidal to settleable materials) originating from the ore itself, from waste material, or from surface installations. These solids can affect aquatic flora and fauna and physically choke local waterways and lakes.

In addition to causing water pollution, excavations can also influence the hydrology around the excavated area. Excavations may lead to more rapid seepage into the groundwater, causing nearby streams or wells to become dry. Underground works may cut across aquifers and bring otherwise separate bodies of water into communication.

 

1. Выпишите из текста отглагольные существительные и переведите их.

2. Выпишите из предпоследнего предложения третьего абзаца придаточное предложение, укажите перевод союзного слова, присоединяющего придаточное предложение к главному. Переведите придаточное предложение, обращая внимание на порядок слов при переводе.

3. Выпишите из текста случаи употребления as, определите его функцию и переведите вместе с относящимися к нему словами.

4. Найдите в тексте слово-заместитель ранее употребленного существительного и переведите его, определив замещаемое им слово.

5. Выпишите из четвертого абзаца последнее предложение. Укажите количество придаточных предложений и союзы, присоединяющие придаточные предложения. Переведите всё предложение.

6. Выпишите из последнего абзаца герундиальный оборот. Переведите его придаточным предложением. Помните, что действие, выраженное герундием, стоящим в начале предложения, относится к подлежащему.

7. Найдите в последнем абзаце инфинитивный оборот и переведите его.

8. Переведите текст с учетом выполненных заданий.

 

Text 24

Industry and Environment (South Africa)

The focus is on local and regional environmental impacts and benefits, with lower priority being given to global impacts. For example, introducing low-smoke coals to reduce urban air pollution will in effect increase CO2 emissions due to the energy required by the devolatilization process, as well as the product's lower energy content.

The primary environmental issues are presented with a South and Southern African perspective below. It should be noted that the attention given to environmental matters in the region varies considerably from country to country.

These issues clearly receive varying attention as components of environmental impact assessments on a project by project basis:

Water quality and availability

Availability of water is one of the critical environmental issues in Southern Africa. Water supplies are highly variable, in terms of both quality and quantity. Technology choices are often strongly influenced by the amount of water used, as well as the impact on water quality.

Land management/ecological impacts

While land is generally readily available, the ecological impacts of a particular technology require assessment, especially in areas where eco-tourism is an important consideration. The inundation of land by hydro projects is an issue requiring particular attention.

Air quality

Power plant emissions receive varying degrees of attention. In general, a holistic approach is adopted with respect to air quality. In South Africa, air quality is assured via use of a "best practicable means" approach. This implies that primary attention is paid to particulate removal, and then the impacts of SOX and NOX are managed via ambient air quality requirements. The Department of Environmental Affairs and Tourism is currently investigating this management process. Acceptable air quality levels are maintained through combustion of low sulphur coals and tall stacks.

It should be noted that extensive research into air quality has been undertaken in the main South African power generation region, Mpumalanga, over a 15-year period. This research has clearly demonstrated the efficacy of the current air quality management processes in maintaining local and regional air and rain qualities at acceptable levels. Air quality has improved by an average of 4% annually for the last ten years, greatly allaying concerns related to exceedance of local and regional air pollution standards. WHO levels for ambient air quality are rarely exceeded.

 

 

Waste management

Production of waste, especially large quantities of fly ash from the combustion of high ash coal, requires careful management. An important component of technology assessment is ash disposal and utilization and the rehabilitation of disposal sites. In addition, the water used in waste transport and disposal is an important consideration in technology choice.

 

1. Найдите в тексте независимый причастный оборот и переведите его.

2. Выпишите из текста герундий в функции подлежащего и переведите его вместе с относящимися к нему словами и сказуемым.

3. Выпишите из текста все составные предлоги и переведите их.

4. Найдите в тексте безличные предложения и переведите их.

5. Выпишите из четвертого и шестого абзацев сказуемые в страдательном залоге и переведите их вместе с подлежащими.

6. Выпишите из седьмого абзаца причастие I в функции обстоятельства и переведите его вместе с относящимися к нему словами.

7. Выпишите из пятого абзаца сложноподчиненные предложения, определите вид придаточных предложений, укажите союзы и союзные слова, присоединяющие придаточные предложения к главному. Переведите все предложение.

8. Переведите текст с учетом выполненных заданий.

 

Text 25

Postpeak Behavior of Fiber-Reinforced Concrete under Cyclic Tensile Loads

The frequent use of special structures subjected to dynamic, as well as the use of high-strength concrete (HSC) to reduce the weight of the structure, has increased the interest in the fatigue behavior of concrete. Because cracks are often present in concrete elements from the beginning of their life due to drying shrinkage or thermal gradients, the assessment of ultimate strength or the behavior under service loads of a structure often necessitates an investigation of the cracking behavior of concrete under cyclic loads.

The study of fatigue behavior of concrete began at the turn of the century with the construction of early reinforced concrete bridges. A sizeable body of knowledge has been accumulated since then, although most of it is related to fatigue of concrete in compression. When referring to fatigue, a distinction should be made between low-cycle fatigue, that involves few load cycles (<103 to 104) with high stresses (similar to those induced by earthquakes); and high-cycle fatigue, characterized by a larger number of cycles with lower stresses (such as those induced by rotating machines). The latter has been the target of the majority of research in the literature, while only in the 1950s did research efforts begin to be devoted to earthquake actions on concrete structures.

Experimental results from fatigue tests show that the process of unloading and reloading in compression causes significant additional cracking or crack widening that, in the case of high-cycle fatigue, mainly concerns the matrix-aggregate interface. For low-cycle fatigue, however, the additional cracking or crack widening occurs in the matrix itself. On the other hand, if cyclic tensile stresses are present, concrete damage mainly occurs in the microcracked zone present at the crack tip (fracture process zone [FPZ]). Hence, the fatigue behavior of concrete structures subjected to tension or bending loads can be correctly studied only by considering the presence of an FPZ. Experimental results from uncracked specimens (even if notched) mostly provide information on the overall behavior of concrete in tension but does not simulate the damage in a real structure where cracks are present.

 

1. Выпишите из первого и третьего абзацев слова с окончанием –ing, определите, какой частью речи они являются, а также их функции и переведите их вместе с относящимися к ним словами.

2. Найдите в тексте слова-заместители ранее употребленных существительных и переведите их, определив заменяемые ими слова.

3. Выпишите из текста сказуемые в страдательном залоге, в составе которых имеется модальный глагол, и переведите их вместе с подлежащими.

4. Найдите в тексте случаи употребления слова that, определите его функции и переведите вместе с относящимися к нему словами.

5. Найдите во втором абзаце текста глагол to do, определите его функцию и переведите ту часть предложения, в которой имеется глагол to do, обращая внимание на инверсию.

6. Выпишите из второго абзаца причастие I в функции обстоятельства и переведите его вместе с относящимися к нему словами.

7. Выпишите из последнего предложения текста слова с окончанием –ed, укажите, какой глагольной формой они являются, определите их функции и переведите вместе с относящимися к ним словами.

8. Переведите текст с учетом выполненных заданий.

 

Text 26

Postpeak Behavior of Fiber-Reinforced Concrete under Cyclic Tensile Loads (continued)

Furthermore, the size of the FPZ depends on the specimen geometry and size, so that different results will be obtained by testing structural specimens such as wedge-splitting or beam specimens with different sizes. This would also explain the dependence on the loading history and the sequence effect, as well as the inapplicability of the Palmgren-Miner Rule to determine the fatigue strength of concrete structures. A better evaluation of the maximum number of cycles with program loading cyclic tests was obtained by determining the total number of cycles to failure for each load block of the loading history from the slope of the linear branch of the cyclic creep curve, which takes into consideration the previous loading history as well as the actual damage in the FPZ.

The cracking-related phenomena governing the fatigue behavior of concrete highlight the potential benefit of the presence of fibers. The use of fibers should be even more effective in HSC which, because its more homogeneous microstructure and the intragranular nature of the cracking phenomenon, is characterized by a particularly brittle postpeak behavior. In fact, the use of fibers increases ductility and thus helps HSC be a high-performing material. The use of fibers also results in a reduction of the crack width that is of primary importance in many reinforced concrete structures, as it is believed that there is a strong correlation between the crack width and the durability of the structure.

The aim of the present work is to shed some new light on low-cycle fatigue behavior of cracked concrete by comparing the material and the structural response. To this end, postpeak uniaxial tensile tests on cylindrical specimens for the study of the material behavior, and four-point bending tests on beam specimens for the study of the structural response, were performed. In particular, the potential benefit of steel and carbon (polyacrylonitrile) fibers was investigated for both normal strength concrete (NSC) and HSC.

To provide a more complete study of the material behavior, both cycles on the envelope curve and cycles within the envelope curve (inner loops) were applied. Static tests were also performed to determine the fracture properties of the materials. Specimens of different sizes were tested to illustrate the size effect that characterize the fatigue behavior of concrete beams. Finally, the increase in the experimentally determined crack-opening during inner loops is compared with an empirical model previously proposed by the authors.

 

1. Выпишите из текста сказуемые в страдательном залоге и переведите их вместе с подлежащими. Обратите особое внимание на те случаи, где необходим обратный порядок слов при переводе.

2. Выпишите из текста герундии в функции обстоятельства и переведите их вместе с относящимися к ним словами.

3. Найдите в тексте предложение со сказуемым в сослагательном наклонении и переведите сказуемое вместе с подлежащим.

4. Выпишите из текста инфинитивы в функции обстоятельства и переведите их вместе с относящимися к ним словами.

5. Найдите в тексте безличное предложение и переведите его.

6. Найдите во втором абзаце предложение с конструкцией There + be и укажите перевод этой конструкции.

7. Выпишите из текста сказуемые с глаголом to be в качестве связки и переведите их вместе с подлежащими.

8. Переведите текст с учетом выполненных заданий.

 


Приложения

Таблица 1

Личные местоимения Притяжательные местоимения
Именительный падеж Объектный падеж Присоединительная форма Абсолютная форма
I He She It We You They я он она он, она, оно (обозначает неодушевленные предметы) мы ты, вы   они me him her it us you them меня,мне… его,ему… ее,ей… его,ему… ее,ей     нас,нам… тебя,тебе; вас,вам их,им… my his her its our your their мой его ее его, ее   нам твой, ваш   их mine his hers its ours yours theirs
всегда подлежащее в предложении всегда дополнение в предложении, отвечает на вопросы косвенных падежей предшествует существительному как определение, отвечает на вопрос "чей?" никогда не сопровожда- ется существительным
             

 

Таблица 2

Местоимения many, much, few, little

Исчисляемые существительные (одушевленные и неодушевленные) Неисчисляемые существительные
Many few a few много мало немного, несколько engineers plants much little a little много мало немного water, work
           

 

Таблица 3



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