FEATURES OF GROWTH OF PETIOLATE OAK IN ARTIFICIAL LINEAR PLANTINGS OF THE CENTRAL FOREST-STEPPE

The formation of artificial linear plantations with the participation of pedunculate oak is predetermined by agrotechnical and silvicultural methods of cultivation. Its share among the used other breeds is about 25%. At the age of 33, with the placement of planting places 5.0 x 3.0 m, the pedunculate oak has a high preservation (by 33.9%) in a three-row plantation, in relation to crops from four rows. The protective height in a narrower artificial linear plantation is 10.2 m, which is 1.24 times higher with a width of 20.0 m. In mixed oak-ash crops at the age of 45 years, the best growth and preservation of pedunculate oak is noted in relation to oak plantations pure in composition. For birch-oak crops, the influence of a fast-growing breed is characteristic. At the age of 54, the safety of pedunculate oak is 23.1%, the wind protection height is 19.1 m. Differences in the growth of species are one class of bonitet. In the central rows of pedunculate oak at the age of 30-49 years, the average height has a greater value and a smaller diameter in relation to the indicators of the edging rows (by 7.5-19.9%). A convex transverse profile of the plantation is formed, which is predetermined by the physiological characteristics of the development of the tree species.

CONTINUOUS IMPREGNATION OF WOOD FROM THE END FACE UNDER PRESSURE WITH VARIOUS COMPOSITIONS

Modern impregnating compositions for wood can significantly improve its characteristics. Water-soluble and oily antiseptics, flame retardants, strengthening and plasticizing modifiers, and dyes are used as impregnating compositions. By means of impregnation, substances are introduced into the wood that increase its characteristics such as plasticity, hydrophobicity, bio- fire resistance and shape stability. But, the indicator of certain properties after impregnation of wood with a certain composition depends on the depth of impregnation, on the uniformity of the distribution of the impregnating composition over the entire volume of wood, on the concentration of the impregnating composition in the wood, on the chosen method of impregnation. It also affects which group of impregnability a particular wood belongs to, according to the breed composition, the division is made into 3 groups: 1-easily nourished rocks (birch, alder, beech, aspen sapwood, poplar, pine); 2-moderately impregnated rocks (cedar, oak, ash, maple, linden, pine core); 3-hard- to-impregnate rocks (spruce, larch, fir). Spruce and larch are considered to be almost impervious to deep impregnation of the rocks, because of their clogged pores with resin. In the autoclave method of impregnation with water solutions, the wood must be dried to a humidity of 40% before impregnation, and to a humidity of 30% when impregnated with oily liquids. After impregnation, a re-drying operation follows. Another significant disadvantage of autoclave impregnation is its uneven distribution of the absorbed liquid in the workpieces, in some workpieces too much impregnating liquid penetrates, and in others not enough. In order to avoid two dries and to be able to set the volume of liquid that the wood will absorb, as well as to ensure the uniformity of impregnation over the entire volume of wood, it is proposed to develop a technology and equipment for end-to-end impregnation of coniferous wood from the end under pressure of raw, rounded logs with a diameter of 15-35 cm and a length of 3 m.

Efficiency of Machine Sanding of Wood

We hypothesized that the type of wood, in combination with the grit size of sandpapers, would affect sanding efficiency. Fixed factors were used in the experiment (a belt sander with pressure p = 3828 Pa, and a belt speed of vs = 14.5 m/s) as well as variable factors (three sand belts (P60, P120, P180), six hardwood species (beech, oak, ash, hornbeam, alder, walnut) and three softwood species (pine, spruce, larch)). The masses of the test samples were measured until they were completely sanded. The sanding efficiency of hardwood species is less variable than for softwood species. Maximum sanding efficiency for the softwood ranged from 1 to 2 min, while for the hardwood species, it ranged from 2 to 4.5 min at the start of sanding and then decreased. The average time for complete sanding of the softwood samples was: 87 s (P60), 150 s (P120), and 188 s (P180). For hardwood, these times were 2.4, 1.5, and 1.8 times longer. The results indicate that the factors determining sanding efficiency are the type of wood, and, secondly, the grit size of sanding belts. In the first phase of blunting with the sanding belts, the sanding processes of hardwood and softwood are significantly different. In the second phase of blunting, sanding belts with higher grit numbers (P120 and P180) behaved similarly while sanding hardwood and softwood.

Honey flora of forest plant community

The honey flora of the forest plant community is an important forage resource for the development of beekeeping. That’s why it is desirable to assess species composition and total number of honey plants and to determine the honey reserve of the area of the forest community plant. The forest cover of the Orel region is 9.3%, and this cover is distributed on its territory very irregularly. 257 species out of the total number of honey plants in the region are found in the forests. Deciduous forests are dominant in the Orel region including oak, ash, linden, birch and aspen. The results of studies of flowering plants in the forest plant community showed that there is a sufficient number of honey plants in the forest to provide bee families with nectar from spring to late autumn due to the natural flower-nectar conveyor. The assessment of the honey stock of this community shows that the stock equals 4,872 tons from 203 thousand hectares of forest. And bees can sip only about 30% (1,626 tons). It proves that significant honey reserves are concentrated in the forest plant community of the Orel region. The rational use of these reserves will help to solve the problem of reproduction of new bee families of the aboriginal Central Russian breed and to organize a long honey gathering by bees that provide people of the region with honey.

Adsorption of Tetracycline and Sulfadiazine onto Three Different Bioadsorbents in Binary Competitive Systems

Different antibiotics contained in manure, slurry, wastewater or sewage sludge are spread into the environment. The harmful effects of these antibiotics could be minimized by means of immobilization onto bioadsorbent materials. This work investigates the competitive adsorption/desorption of tetracycline (TC) and sulfadiazine (SDZ) onto pine bark, oak ash and mussel shell. The study was carried out using batch-type experiments in binary systems (with both antibiotics present simultaneously), adding 5 equal concentrations of the antibiotics (between 1 and 50 µmol L−1). The adsorption percentages were higher for TC (close to 100% onto pine bark and oak ash, and between 40 and 85% onto mussel shell) than for SDZ (75–100% onto pine bark, and generally less than 10% on oak ash and mussel shell). Pine bark performed as the best adsorbent since TC adsorption remained close to 100% throughout the entire concentration range tested, while it was between 75 and 100% for SDZ. Desorption was always higher for SDZ than for TC. The results of this study could be useful to design practices to protected environmental compartments receiving discharges that simultaneously contain the two antibiotics here evaluated, and therefore could be relevant in terms of protection of the environment and public health.

Influence of Grit Size and Wood Species on the Granularity of Dust Particles during Sanding

Wood dust poses a threat to the health of employees and the risk of explosion and fire, accelerates the wear of machines, worsens the quality of processing, and requires large financial outlays for its removal. The aim of this study was to investigate the extent to which the grit size of sandpaper influences the size of the wood dust particles and the proportion of the finest particles which, when dispersed in the air, may constitute the respirable fraction. Six species of hardwood (beech, oak, ash, hornbeam, alder, and walnut), and three species of softwood (larch, pine, and spruce) were used in the research. While sanding the samples under the established laboratory conditions, the following were measured for two types of sandpapers (grit sizes P60 and P180): mean arithmetic particle size of dust and finest dust particles content (<10 µm). Based on the obtained results, we found that the largest dust particle sizes were obtained for alder, pine, and spruce; the smallest size of dust particles during sanding with both sandpapers was obtained for beech, hornbeam, oak, ash, larch, and walnut. The mean arithmetic particle sizes ranged from 327.98 µm for pine to 104.23 µm for hornbeam. The mean particle size of the dust obtained with P60 granulation paper was 1.4 times larger than that of the dust obtained with P180 granulation sandpaper. The content of the finest dust particles ranged from 0.21% for pine (P60 sandpaper) to 12.58% for beech (P180 sandpaper).The type of wood (hardwood or softwood) has a significant influence on the particle size and the content of the finest dust fraction.