“Green technology” processing of pine (Pinus sylvestris L.) and larch (Larix sibirica Ledeb.) wood greenery to produce bioactive extracts

In order to explore the extractives of conifers an effective and environmentally friendly method of extraction with aqueous-alkaline solution allowing to isolate up to 10.4% of extractive substances (ES) from pine wood greenery and up to 6.9% from larch wood greenery was investigated. The component fractional composition of aqueous-alkaline extracts was studied. The antioxidant fraction activity of neutral and acidic components isolated from the produced extracts was evaluated. It was found that these fractions have a high antioxidant activity, where the activity of larch extract components was higher than that of the respective components of pine extract. Due to their rich chemical composition and high biological activity, extracts of pine and larch wood greenery produced by aqueous-alkaline extraction have good application prospects as biologically active preparations.

Effects of accelerated weathering test on the properties of larch wood

To investigate the changes of larch wood properties under the influence of long-standing exposure to the environment, the QUV accelerated weathering tester (fluorescent UV and condensation testers) was used to accelerate the weathering of wood within a given preset time, and the changes were studied by analogue simulation. The wood color changed noticeably under different weathering time, and it gradually darkened from light yellow to deep reddish brown. Scanning electron microscopic (SEM) analysis revealed that as the weathering time increased, the cell wall was broken, the pits were cracked, and the tracheids were damaged. The results of the energy spectrum analysis (O/C (oxygen/carbon)) showed an increasing trend in the ratio, indicating that the wood underwent an oxidation reaction induced by light. From the values of the two testing indexes and their change patterns with weathering time, the same trend was observed, with the values of modulus of elasticity (MOE) in static bending being greater than that in dynamic bending Ed (the dynamic modulus of elasticity). However, the variability of MOE was greater than that of Ed. A comparative analysis of the two detection indicators was performed. The relationship between the proposed combined correction Ed and weathering time was: y = 0.0000001017 t2 – 0.0006 t + 9.77.

Propagation velocity model and two-dimensional defect imaging of stress wave in larch (Larix gmelinii) wood

The propagation law of stress wave in larch (Larix gmelinii) wood was studied in this work. External factors affecting the propagation velocity of stress wave in wood cross-section were studied using the orthogonal experiment method. The most influential factors were shown by the experimental results, and the parameters of the propagation velocity model of stress wave in larch wood were optimized. Based on the optimized propagation velocity model, combined with the traditional defect determination method, a twelve-directional stack imaging (TDSI) steps system was developed for larch wood internal defect detection. The analysis results showed that of the three external factors of temperature, moisture content, and illumination duration, temperature had the greatest influence on the propagation velocity model of stress wave in larch wood cross-section. Using TDSI to image the defective larch wood not only can locate the defective area, but also it can achieve a high imaging precision of 95.52%, and the imaging precision is unrelated to the location of the defect, which has a good quantitative defect detection effect.

FEATURES OF GROWTH OF CALVES DURING THE DAIRY PERIOD WHEN USING PHYTOPREPARATIONS

Изучены особенности роста и развития молодняка крупного рогатого скота при выращивании в ранний период онтогенеза после применения фитосредств на основе водно-дисперсной вытяжки из древесины березы и лиственницы, позволяющих активировать обменные процессы в организме и повышать прирост живой массы телят соответственно на 20,3 и 34,5%. Гематологические исследования показывают, что интенсивный рост молодняка сопровождается динамикой содержания в сыворотке крови белка, кальция, фосфора, глюкозы, щелочной фосфатазы, которые в дальнейшем можно использовать в качестве тестов для раннего прогнозирования роста телят в промышленных комплексах. The features of growth and development of young cattle during growth in the early period of ontogenesis after using the phytosupplements on the basis of a water dispersed extract from birch and larch wood allowing to activate metabolic processes in an organism and to increase a gain of live weight of calves by 20,3 and 34,5% respectively have been studied. Hematological studies show that the intensive growth of young calves is accompanied by the dynamics of serum protein, calcium, phosphorus, glucose, alkaline phosphatase, which can be further used as a test for early prediction of calf growth in industrial complexes.

Experimental Study on the Bending Behavior of Steel-Wood Composite Beams

This paper proposes a steel-wood composite beam with H-shaped steel beam webs glued to the wood. As a new type of composite beam, it combines the advantages of low energy consumption of wood, high permeability, and less pollution and the advantages of light weight and high strength of steel, high degree of assembly, short construction period, and less construction waste generated. Carrying out research is of great significance to improve the mechanical properties of steel-wood composite beams and promote the development of steel-wood composite structures. In this paper, three hot-rolled H-beam-larch composite beams and one pure steel beam were tested for bending capacity. The composite beams are divided into two different combinations of A and B types. The two sides of the web are connected with larch wood by structural glue to form a composite beam. The type B composite beam is a larch wood glued on both sides of the H-shaped steel web and penetrates the bolts at the same time. Through the three-point monotonic static grading loading of the composite beam, the deflection change, failure phenomenon, and form of the specimen during the experiment were observed. Under the circumstances, the ultimate bearing capacity of the test piece was changed to study the combined effect of larch and hot-rolled H-shaped steel. The results show that the overall performance of the H-shaped steel-larch composite beam is good. Bonding wooden boards on both sides of the steel beam web can improve the bearing capacity, and the form of the member is more reasonable and effective; increasing the cross-sectional size of the H-beam in the steel-wood composite beam can further improve the bearing capacity of the composite beam; adding bolt anchorage on the basis of the structural glue used in the composite beam can further improve the bearing capacity of the composite beam. The superposition principle is used to simplify the calculation of the ultimate bearing capacity of H-shaped steel-larch composite beams. Comparing the calculation results with the test results, the data are in good agreement, which can provide a design reference for the practical application of such composite beams.