Pear. In our country grows 35 wild species of pear. Pear Common – tree up to 25 m, and sometimes large shrub with thorny branches. It grows in groups and singly in oak-leaved forests and steppe steppe zone of European Russia, Crimea, the Caucasus and Central Asia. In Kursk and Voronezh regions forms in some places pear wood. This species is the ancestor of many cultivated varieties of pears. The fruit on long legs, as an opportunity to clean the pads on the equipment for clean pillows, a variety of size and shape, usually spherical or pear-shaped, 2-4 cm in diameter.
Unattractive in appearance, usually green, sometimes reddening, astringent, rough stony flesh, making edible in September, the overripe condition when the flesh becomes brown, pasty. The fruits contain a wild pear,% sugars – 3-10, pectin – to 1.2 titratable acids – 0,22,7, as well as about 22 mg% of vitamin C and 330-3320 mg% tannins and pigments. Sugars are mainly glucose and fructose, sucrose, contains up to 0.6%. Need cleaning pads. Of carboxylic acids is dominated by malic, citric, and there are few traces of amber. Emergency tartness of fruit wild pear is not so much due to the high content of polyphenol compounds, as their quality, especially oksikorichnymi acids, represented by chlorogenic, quinic, caffeic, coumaric.
Their number may reach 70% of the polyphenol compounds. When ripe, the fruit and the total content of tannin stains reduced. Almost all species of wild pears are small fruits with the restoration. The fruits are used as food in fresh form, as raw material for various food industries. From them prepare compote, cider brew. Dried fruits receive substitute coffee and tea. Fresh fruits, which are used after maturation – a valuable product that promotes better digestion. Juice and fruit extracts are used for stomach disorders and as a diuretic, and broths have antipyretic properties.
Fall height); Water absorption (Water absorption); Abrasion (Frictional wear test); Density (Bulk density). Color of the stone, or rather op definition of visual sensation caused by the impact on the eye fluxes of electromagnetic radiation in the visible spectrum, it is an important physical property. In general, the color of the rock due to the predominant color giving in its composition of minerals and impurities. He determined by the so-called "average color" when the colors of various rock-forming minerals are merged into one common tone. The color of minerals depends on their chemical composition. Thus, the white marble consists mainly of colorless dolomite and calcite that . Gray tones are determined by the presence of carbonaceous or other organic particles, and pink – salts of manganese or iron oxide, green – chlorite and serpentinite particles, and sometimes copper oxides.
Color igneous rocks deter mined colored minerals: quartz, feldspar and dark color components. Color is a very important sign, turn out equation describing crucial in assessing the decorative stones. Structure Natural stone is characterized by the shape and proportions generated doobrazuyuschih minerals, particularly styami its structure and size. Structures are crystalline (granular and crystalline), porphyry, detrital, Stack Lovato oolitic, etc. Marble (Latin marmor, from Greek.
Marmaros – shiny stone, boulder), crystalline rock formed by the recrystallization of limestone or dolomite. In construction practice "Marble" is called metamorphic rocks of medium hardness, polishing makers, these include: marble, limestone marmorized, dense dolomite, carbonate breccias and calcareous conglomerates. Marble almost always contain impurities other minerals and organic compounds. The composition of impurities can lower or raise the decorative marble and affect its color. Image is determined not only the structure of marble, but also direction in which you are sawing stone. Color and pattern of marble occur only after polishing. Marble from the ancient times used as a structural and architectural cladding material due to its plastic and decorative merits (hardness, fine grain, which makes the marble in the treatment of pliable, able to make polished, through which identifies the tonal richness of marble and the beauty of his homogeneous, speckled, or layered structures). Marble is also used to create the mosaic compositions, relief and round sculptures (mostly monochrome marble, mostly white, at least – a color or black).