Thirteen of the essential elements are minerals. These naturally occurring, inorganic substances become available to plants in ionized form. Six of these minerals are called macronutrients; each makes up the plant. The rest are micronutrients, or trace elements, which represent only a few parts per million of the plant’s dry weight.

Essential trace elements are required by man in amounts ranging from 50 micrograms to 18 milligrams per day. Acting as catalytic or structural components of larger molecules, they have specific functions and are indispensable for life.

In general, the physical environment serves as a large reservoir through which elements move rather slowly, compared to haw rapidly are exchanged between organisms and the environment within the ecosystem. Broadly speaking, oxygen and hydrogen move in the form of water cycle, whereas carbon and elements move through atmospheric and sedimentary cycles.

In atmospheric cycles, the elements occurs in a gaseous phase and a large portion of it exists in the atmosphere. In sedimentary cycles, the elements does not have a gaseous phase; it moves from land to sediments in the oceans, then back to the land through geological uplifting over immense spans of “geological” time. Time of biological turnover of the elements essential for life (biogens) is estimated as 10 to 30 years for land ecosystems and about 10 days for oceanic ecosystems, whereas the geologic turnover time is 10.000-100.000 years.

Nitrogen is one of the macronutrients. It is the component of all proteins and nucleic acids. The atmosphere is the largest nitrogen reservoir: nearly eighty percent of it is composed of gaseous nitrogen N2. The N2 molecules are held together by stable, triple covalent bonds (NN), and few organisms have the metabolic equipment for breaking them.
Nitrogen fixation is a process in which a few kinds of bacteria (nitrogen fixes) convert gaseous nitrogen N2 to ammonium NH3 which dissolves rapidly in water to produce ammonium NH4+. The fixed nitrogen is used by bacteria in the synthesis of amino acids, then of proteins and nucleic acids. Today, nearly all the nitrogen in soils has been put there by a variety of nitrogen-fixing organisms.
Nitrification:

Fixed nitrogen is lost to the soil because ammonia, nitrite, and nitrate are soluble and readily washed out of the soil.
Also, fixed nitrogen is lost to the soil through a bacterial process called denitrification: Under anaerobic conditions, denitrifying bacteria change nitrate to gas N2 , which gradually escapes into the atmosphere.

Denitrification:
Since the beginning of life, nitrogen has been abundant in the atmosphere and oceans but scarce in the Earth’s crust. Of all nutrients influencing the grows of land plants, nitrogen is often the one in shortest supply. Unlike natural ecosystems, in which nutrients such as nitrogen are cycled, modern agriculture exists only due to constant, massive infusions fertilizer.

3.Lasers are now used for many scientific, medical and industrial purposes. The thin beam of light gives a lot of heat and it is used to join metal when a very small joint is needed. The beam can also be used as a drill, to make holes in steel, or even in diamonds. Because the beam is so small, it very important in delicate surgery and is used in eye operations.

4.Lasers arc also used in holography. A hologram is a, three-dimensional image, a bit like photograph. It’s different from a photograph because it looks solid. As you walk round a hologram, it changes, as if it were real. Now holography is used for testing engineering ideas. An engineer can use a hologram to build up and check a new building such as a bridge. He can find out all about it before he builds it.

5.The word MASER is also an acronym — for Microwave Amplification by Stimulated Emission of Radiation. The masers operated on the same principle as the laser except that the wavelengths generated are much longer and therefore the energy jumps involved are smaller. The excited bodies in a maser are molecules rather than atomic electrons and the beam generated is a coherent beam of microwaves which is not visible to the eye.

6.Masers have made revolutionary advance possible in a number of different fields, i hey are up to 1.000 times more sensitive than any other type of amplifiers.Masers amplifiers mounted on radio telescopes can increase even their great range by a factor of 10 allowing us to reach out to the bounds or the known universe, because or the very constant frequency with which masers can be made to oscillate they can be used as master controls for atomic clocks of unbelievable accuracy an error not exceeding 1 second in 10.000 years has already been achieved.

7.The idea of using stimulated emission of radiation for amplification of very short waves came from A.Prokhorov and N.Basov of the Lebedev Institute in Moscow.

In 90th years Japan has fixed itself, as the leading country on robotics manufacture. Mechanical assistants, have been created for the most different purposes, but the primary goal of the Japanese inventors, creation of the daily assistant for the person is. The Japanese developers plan to make so that by 2014 in each Japanese family there would be a robot.

Now the outcome approaches to it. Now still it is impossible to tell that the robot is at everyone, but in some Japanese families already there are robots assistants who not only do a housework, but also play with children. All gradually moves to that, the Japanese inventors assume.

The robotics already brings in now to Japan enormous incomes, but not only Japan will attach to this science a great attention. Its basic competitor on robotics creation is South Korea in which this branch develops not less.
The largest Japanese companies on manufacture of robots ZMP Inc., Vstone Co, and Tmsuk the special association which participants should promote creation of a commodity market for a robotics of following generation is already created. Except market working out, these companies work over working out and advancement of unique production.
Having looked at modern technologies and on rate of their development, it is possible to tell that the future which was described by Isaac Azimov any more behind mountains.