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Контрольное задание № 3 Вариант № 1

(Автоматизация)

Flexible production and industrial robots

This country’s machine-building industry is now facing the task of restructuring on a large scale engineering production, and developing new methods of organization, new equipment and new technologies. This is a global process. Swift production, the introduction of microprocessors, robotics, rotary and rotary-conveyer lines, flexible readjustable production is vital for today’s industry.

Industrial robots play an important part in the process. Many institutes are currently engaged in developing them. The concept of designing robot modules is making successful headway.

The task today is to raise their reliability, speed and failure-free operation.

Also needed for the operation of flexible production systems which will transport billets and parts between machine-tools, transports robots, robot trailers as well as measuring robots. Experts from the Institute of Machine Studies are developing measuring manipulators and coordinate-measuring machines.

It is hard to enumerate all the problems facing our engineers and designers in the development of flexible productions. Automated systems of adjusting, controlling instruments, machined parts and many other things are needed.

(Промышленная электроника)

Hardware

What is hardware? Webster’s dictionary gives us the following definition of the hardware – the mechanical, magnetic, electronic and electrical devices composing a computer system.

Computer hardware can be divided into four categories:

1. input hardware

2. processing hardware

3. storage hardware

4. output hardware

Input hardware

The purpose of the input hardware is to collect data and convert it into a form suitable for computer processing. The most common input device is a keyboard. It looks very much like a typewriter. The mouse is a hand held device connected to the computer by small cable. As the mouse is rolled across the mouse pad, the cursor moves across the screen. When the cursor reaches the desired location, the user usually pushes a button on the mouse once or twice to signal a menu selection or a command to the computer.

The light pen uses a light sensitive photoelectric cell to signal screen position to the computer. Another type of input hardware is optic-electronic scanner that is used to input graphics as well as typeset characters. Microphone and digital camera can be also used to input data into the computer.

(Электроснабжение)

Electricity

Modern electron theory views matter as basically electrical and the atom, the basic unit of matter, as composed of negative charges (electrons), positive charges (protons) and neutral particles (neutrons).

Electrons move within the atom in orbits around the nucleus and sometimes move to another atom. The loss of an electron leaves the atom positively charged: the gain of an electron charges it negatively.

Static electricity is concerned with the nature, strength and effect of charge on bodies. The ways of charging a body include bringing it close to a charged body, rubbing a glass rod with silk and rubbing a hard rubber rod with flannel.

The capacity to receive and hold charge varies. Some metals called good conductors pass the charge on rapidly, some other materials are poor conductors. In solid conductors current flow results from the movement of many electrons.

In electrolytic and gaseous conductors both positive and negative charges move either way from electrode to electrode. Electric current (or electron flow) is set up in a conductor when it connects cell electrodes forming a closed electric circuit. A one direction flow of electrons is called direct current. A generator current (if no commutator is used) alternates the direction of the flow (current). That kind of current is called alternating current.

(Химия)

Ion-selective electrodes

The conventional cell arrangement for potentiometric measurements using an ion-selective electrode is: internal reference element and solution / ion-selective membrane / sample solution / external reference electrode. In this configuration the internal aqueous reference solution which contains the ions necessary to maintain constant potentials at both the reference element and the inner surface of the ion-selective membrane is held at a constant composition. Potentials at both reference elements may thus be considered as constant and the form of the dependence of the potential difference across the cell on the composition of the sample solution will be determined by the potential difference across the membrane. The latter is determined by the boundary potentials at the two membrane / solution interfaces and any diffusion potentials which arises as a result of variation in the counter-ion composition through the membrane.

Boundary potentials arise from the separation of charge which occurs in the region of the membrane / solution interface as a result of the differences in free energies of transfer from the membrane to the aqueous phase that exist between lipophilic ions in the membrane and their counter-ions. Usually it is assumed that the lipophilic ions are confined to the organic phase.

(Машиностроение)

Machining of metals

The machining of metals is the processes of removing chips from the metal parts. These processes include turning, planning, shaping, drilling, boring, reaming, sawing, broaching, milling and grinding. They have been greatly developed since the development of the steam engine. Machining operations lie at the basis of all modern industrial production. In the design of a modern machine of any type are reflected the latest developments of practically all the other engineering industries. Six chief hard materials are used in machining as cutting tools. These are diamonds, carbon, tool steel, high-speed steel, satellite carbides and abrasive materials.

The strict distinction between the operations of drilling and boring is that the first initiates a hole, while the second enlarges one already existing. Reaming is the operation enlarging a machined hole to accurate size with a smooth finish. The sawing of materials is an important operation too.

Broaching is a machining method in which one or more cutters (broaches) with a series of teeth are pushed or pulled across a surface to machine that part to the desired shape. The broach has a number of successive teeth of increasing size which cut in a fixed path. Grinding is the only method of cutting such materials as hardened steel. Grinding is performed with a rotating abrasive wheel. Cylindrical, internal, surface and centreless grinders are common types.

(Гражданское строительство)

The use of Pyramidal piles in building

Pyramidal piles are a progressive design of piles used in building. These piles have the shape of an enlarged pyramid; they are rammed into the ground, acute end first. Unlike prismatic piles, pyramidal piles pack the soil along the sides while sinking into it, thus enhancing the mechanical quality of the soil, and subsequently conveying the load of the whole side surface upon the packed basis.

Such distinctive features of the work of prismatic and pyramidal piles in the basis soils ensures the possibility to enhance the bearing capacity of pyramidal piles with respect to prismatic piles by 1.5-2 times.

Pyramidal piles are used in the basis of buildings and constructions for various purposes and designs. They are especially effective when packed soil lies on the upper part of the basis from 3 to 5 m deep, while loose soil can lie underneath.

In this case pyramidal piles must work as single piles. When pyramidal piles are arranged in groups and joined by a low foundation raft, the depth of the loose soil should be taken into consideration as well as the number of piles in the group. If the basis is made up of packed soil along the whole depth, the number of piles in the group is not limited.

The structural design of pyramidal piles is carried out in accordance with the deformations, proceeding from the equality of the work of external and internal forces with due regard for obligatory requirements. The volume of the stabilization zone should not exceed the volume of the consolidation zone while conveying the load to the pile.

(Экология)

Ecosystems: What they are

Photographs of the earth taken from the moon made it clear as never before that the Earth is a sphere in the void of space like a spaceship on an everlasting journey. "Spaceship Earth" became a popular term and concept. Spaceship Earth is unique among all the planets we know. In addition to its rock base, it has an oxygen-rich atmosphere, an abundance of liquid water, and, most conspicuous, millions of kinds of living things of which we, Homo sapiens, are but one. The layer around the Earth where air (atmosphere), water (hydrosphere), and minerals (lithosphere) interact with living things is called the biosphere.

No living organism exists or can exist as an entity unto itself. Each organism is but one member of a particular species. The word "species" refers to the total population of a specific kind of plant, animal, or microbe. But no species is an entity unto itself either. All species depend on air, water, and nutritive elements from the earth's minerals. But plants, animals, and microbes also play important roles in removing pollutants from air and replenishing its oxygen and carbon dioxide, in purifying water, and in recycling mineral elements. Therefore, we can say that plants support animals; animal activities support plants; and all organisms help to support and maintain air, water, and soil quality.

(Автомобилестроение)

Engine

An engine produces power by burning air and fuel. The fuel is stored in a fuel tank. The fuel tank is connected to a fuel pipe. The fuel pipe carries the fuel to a fuel pump. The fuel pump is connected to the carburetor. The fuel pump pumps the fuel into the carburetor. In the carburetor the fuel is mixed with air. The fuel and air are drawn into the engine cylinder by the piston. Then the fuel and air are compressed by the piston and ignited by the spark plug. They burn and expand very quickly and push the piston down. Thus the power is produced. The burned fuel and air are expelled from the cylinder by the piston.

The flow of gases into and out of the cylinder is controlled by two valves. There is an inlet valve allowing fresh fuel mixture into the cylinder and an exhaust valve which allows the burnt gases to escape.

There are two basic engine operating cycles: a) the four-stroke cycle; b) the two-stroke cycle.

The complete four-stroke cycle comprises: 1. the induction stroke (the piston moves downwards); 2. the compression stroke (the piston moves upwards); 3. the power stroke (the piston moves downwards); 4. the exhaust stroke (the piston moves upwards).

(Экономика)

Strengths and Weaknesses of Different Forms of Business Organization

Proprietorships, partnerships and corporations have certain advantages and disadvantages. These can be considered using the following criteria: simplicity, ability to raise capital, liability, control, taxation, etc.

Of the three basic forms, the proprietorship is the simplest. The legal procedures for starting a proprietorship are limited to registering the company's name. Going out of business is also very easy: no legal procedures are required. Starting a partnership is less complex than starting a corporation, but somewhat more so than starting a proprietorship. Simplicity has its advantages but it is not the only thing to consider when choosing the right form of business organization.

Ways of raising capital are different under different forms of business organization. The source of capital for a proprietorship is usually the owner's own savings and loans from banks. More capital can be raised by bringing in partners or by incorporating. The so-called venture capital market is another important source of capital for new businesses.

A major difference among organizational forms is the degree to which owners are personally liable for debts of the business. If a proprietorship fails, creditors can claim the owner's property to payoff the debts of the business.

For a partnership, liabilities can also be a serious problem. The limited liability feature of the corporation is its biggest advantage.