Контрольное задание № 4 Вариант № 1

(Автоматизация)

Application of automated guided vehicle (AGV)

1. The AGV is a system in which identical vehicles load, unload and transport loads under computer control, without a human operator on board. Directional control is provided by some type of guide path, mounted in the floor or transmitted via radio messages. The network and the carts are controlled by base computers, on-board computers and local traffic control devices which also communicate with the overall FMS control system.

2. The major benefits of using AGV systems in FMS are as follows: The route of the AGVs can be easily altered, expanded and modified, simply by changing the guide path of the carts. This procedure is more effective than modifying fixed conveyor lines or railed carts. It provides a direct access to material handling system for loading and unloading FMS cells and accessing AS IRS (Automated Storage and Retrieval System). In this way new and already existing cells can be linked one-by-one to the overall materials handling system provided that each cell has the necessary control interface and is mechanically compatible with the AGV system.

(Промышленная электроника)

Output hardware

The purpose of output hardware is to provide the user with the means to view information produced by the computer system. Information is output in either hardcopy or softcopy form. Hardcopy output can be held in your hand, such as paper with text (word or numbers) or graphics printed on it. Softcopy output is displayed on a monitor.

Monitor is a component with a display screen for viewing computer data, television programs.

Printer is a computer output device that produces a paper copy of data or graphics.

Modem is an example of communication hardware – an electronic device that makes possible the transmission of data to or from computer via telephone or other communication lines.

Hardware comes in many configurations depending on what the computer system is designed to do. Hardware can fill several floors of a large office building or can fit on your lap.

(Электроснабжение)

Electrostatics

In the study of electricity it is customary to divide the subject into electrostatics and electrodynamics. The first deals with electricity at rest, the second with electricity in motion. This division of the subject is convenient because electricity in motion has important properties that are not possessed by electricity at rest. One of these extra properties is the production of a magnetic field by a wire when carrying a "current" of electricity; another is the heating of the wire, and still another is the side thrust experienced by the wire if it cuts across a magnetic field produced by some other source. This last property is utilized in all electric motors. We must weep in mind, however, that the minute electrically charged particles, electrons and protons are essentially the same whether in motion or at rest. If a rod of sealing wax, glass, or of hard rubber is rubbed with flannel or silk, it is found that both the rod and the object with which it is rubbed, exhibit for a short time a slight attraction for bits of paper, cork and other materials. It is said that bodies which exhibit this sort of attraction are electrified and the agency which imparts this property is called electricity or an electric charge.

(Химия)

Photoreactions in bulk polymers

Photoreactions in polymers are of great interest for various reasons and particularly in connection with the use of a polymer as a matrix for a photoinduced reaction, e.g. photoimaging processes. However, in most cases considerable deviations from solution are observed if the reaction is carried out in a solid polymer matrix, a phenomenon, which so far was ascribed to the viscoelastic properties of polymers in general. Systematic investigations of the photochromism of aromatic azo compounds and spiropyrans as models for photoactive compounds in a series of polymers revealed that the free volume and the molecular mobility of both the photoactive compound and of the polymer chains are the reaction controlling parameters. This is demonstrated, e.g., for the case of aromatic azo compounds (cis-trans isomerization around the azo linkage) in the temperature dependency of aT (ratio of the thermal cis-trans relaxation time at temperature T to its value at T g) in the reduced Arrhenius-plot.

The reduced Arrhenius-plot exhibits the existence of two different relaxation mechanisms of the azo chromophore in the glassy polymers, both with temperature independent energies of activation which are found to be much lower than in solution. These values coincide with the characteristic energies for rotational and translational chain segmental motions in glassy polymers. It is therefore concluded that only chain segmental relaxation processes which depend on the local environment of the chromophore are the controlling factors for the isomerization.

(Машиностроение)

Dies

Dies are tools used for the shaping of solid materials, especially those employed in the press-working of cold metals.

In presswork, dies are used in pairs. The smaller die, or punch, fits inside the larger die, called the matrix or, simply, the die. The metal to be formed, usually a sheet, is placed over the matrix on the press. The punch is mounted on the press and moves down by hydraulic or mechanical force.

A number of different forms of dies are employed for different operations. The simplest are piercing dies, used for punching holes. Bending and folding dies are designed to make single or compound bends. A combination die is designed to perform more than one of the above operations in one stroke of the press. A progressive die permits successive forming operations with the same die.

In coining, metal is forced to flow into two matching dies, each of which bears an engraved design.

In the manufacture of wire, a drawplate is usually employed. This tool is a metal plate containing a number of holes, successively less in diameter and known as wire dies. A piece of metal is pulled through the largest die to make a coarse wire. This wire is then drawn through the smaller hole, and then the next, until the wire is reduced to the desired measurement. Wiredrawing dies are made from extremely hard materials, such as tungsten carbide or diamonds.

(Гражданское строительство)

The roof

The roof is a necessary component of practically every building. It serves to protect the interior of the building from rain, snow, wind, and cold. There exist many types of roofs, the main ones being sloping (pitched) roofs and flat (or nearly flat) ones.

It is a well-known fact that every roof should have a covering. The type of covering of a roof mainly depends on the form of the roof and some other factors. The pitched roof is known to dry itself quickly of water. Therefore it can be covered with roofing materials consisting of small individual units. To these belong, for example, slate, shingles of wood, tiles of fired clay or concrete. These materials are widely used and popular as roofing coverings since they have a number of useful qualities. Firstly, the small units they consist of are easy to install. Secondly, they are easy to repair since they are individual and small. Thirdly, it should be taken into account that they are rather cheap. So if a pitched roof is manufactured of properly chosen material and is well installed, it looks beautiful and attractive. But, of course, pitched roofs have their disadvantages. Roofs of this kind should not be installed on broad and large buildings. They do not look attractive on such buildings. As to flat roofs, they can cover very broad buildings. Another advantage of these roofs is that they can serve as balconies and decks and even be landscaped parts of buildings they cover. But they also have some disadvantages. One of them is that water evaporates too slowly from their surfaces.

(Экология)

Ecosystems: What They Are

There are two "sides" in every ecosystem, the organisms on one hand and the environmental factors on the other. All the organisms – plants, animals, and microbes – in the ecosystem are referred to as the biota (bio, "life"). The way the categories of organisms fit together is referred to as the biotic structure. The nonliving chemical and physical factors of the environment (climate, soil quality and so forth) are referred to as abiotic (a, "non") factors.

As it was noted before, the environment involves the interplay of many physical and chemical, or abiotic factors, the major ones being rainfall (amount and distribution over the year), temperature (extremes of heat and cold as well as average), light, water, wind, chemical nutrients, pH (acidity), salinity (saltness) and fire. The degree to which each is present or absent, high or low, profoundly affects the ability of organisms to survive. However, different species may be affected differently by each factor. We shall find that this difference in response to environmental factors determines which species mayor may not occupy a given region. In turn, which organisms do or don't survive determines the nature of a given ecosystem.

In any study of the abiotic side of ecology, the key observation is that different species thrive under different conditions. This principle applies to all living things, both plants and animals.

(Автомобилестроение)

Brakes

Brakes are used to slow or stop the car where it is necessary. It is one of the most important mechanism of the car as upon its proper performance the safety of passengers depends. Car brakes can be divided into two types, namely: drum brakes and disc brakes. The drum type may be either a band brake or a shoe brake. Depending on their functions, the automobile has foot brakes and hand brakes. According to their mode of operation, the brakes are classified as: mechanical brakes, hydraulic brakes, air brakes, electric brakes. Brakes are controlled by the brake pedal.

Most braking systems in use today are hydraulic. This system consists of a master cylinder mounted on the car frame and wheel cylinders. When the driver pushes down on the brake pedal it forces the piston to move in the master cylinder and brake fluid is delivered from move and the brakes are applied.

The air brake uses compressed air to apply the braking effort against the brake shoes.

Electric brakes use electromagnets to provide the braking effort against the brake shoes.

Formerly brakes were applied only to the rear wheels, but now all cars equipped with all-wheels brakes. Today many improvements are being made in brakes.

(Экономика)

Fiscal sphere

Fiscal policy is the policy adopted by a government for raising revenue to meet expenditure. For countries that now face unsustainable fiscal deficits, financial stabilization represents a top priority.

The answer to financial stabilization lies in the effectiveness of fiscal management – the principles, institutional arrangements, information flows, and techniques that govern the budget process and define fiscal relations between levels of government.

Most western nations operate some degree of fiscal federalism, which is the system of taxation and public expenditure in which revenue-raising powers and control over expenditure are vested in various levels of government within a nation, ranging from the national government to the smallest unit of local government.

A system of multilevel finance may be justified in terms of allocative efficiency on the grounds that while some public goods such as national defence, confer benefits on the nation as a whole, the benefits of other goods, such as refuse collection, are more limited· in geographical incidence. It is argued that by making decisions concerning the provision and financing of the latter type of goods at I he level of local rather than national governments, the best or optimal level of provision is more likely to be achieved.

Since the onset of the reforms the Russian Federation has been in I he process of creating a new system of taxation and rules to administer taxes and to distribute those taxes and expenditure responsibilities among levels of government.