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Wood boards find wide application in many fields, especially in house building. Research has been actively conducted in the field of obtaining low-density wood boards in the past 20 years. This article presents the results related to studying the influence of hydrodynamic processing of wood particles (sawdust) on their physical properties and dimensions, for the purposes of identifying the mechanism of autohesion interaction in formation of low-density boards without the binding agents. The particles were processed in a hydrodynamic rotarypulsed disperser. Water retention value (WRV) was used in order to evaluate the degree of processing. A method for determination of water adsorption by wood, and scanning electron microscopy were taken as a criterion of the fibrillation size of wood particles and increase inavailable interphase surfaces as a result of processing. Hydrodynamically processed wood pulp was frozen at –60 oС and then lyophilized in order to preserve its capillary structure. As a result of the study, we have constructed sorption isotherms of the following samples: initial sawdust, sawdust processed in the hydrodynamic disperser and lyophilized, and lowdensity wood boards. It was found out that the sorption isotherms of hydrodynamically processed and lyophilized wood particles are considerably different from the isotherms of initial sawdust and final boards. The calculations made according to the BET method showed that the specific surface area of the processed and lyophilized wood particles is about 350 m2/g of dry weight, and the area of the initial sawdust and obtained boards is approximately 130 m2/g of dry weight. This suggests that hydrodynamic processing allows us to considerably increase the fibrillation of wood particles, thereby increase the area of available interphase surfaces, which creates the conditions for autohesion interaction between the particles. As a result the board structure is formed without binding agents. Thedynamics of changes in the wood particles dimensions under hydrodynamic processing was studied by the scanning electron microscopy. Sawdust crushing and increasing the share of ribbon-shaped particles in the form of partially destroyed tracheids with fibrillated surfaces take place at that. The wood pulp becomes more homogeneous under the high degree of processing (water retention value by the Jaime method – 250 %).For citation: Ermolin V.N., Bayandin M.A., Kazitsin S.N., Namyatov A.V. Structure Formation of Low-Density Boards from Hydrodynamically Activated Soft Wood Waste. Lesnoy Zhurnal [Forestry Journal], 2019, no. 5, pp. 148–157. DOI: 10.17238/issn0536-1036.2019.5.148Funding: The study was carried out with the financial support from the Russian Foundation for Basic Research, the Government of Krasnoyarsk Krai, and the Krasnoyarsk Regional Fund for Scientific and Technical Development Support within the frame of a scientific project “Study of Structuring Materials made of cavitation activated wood”.

The main characteristics of water masses in the Laptev Sea formed as a result of the mixing of Atlantic and river water and transformed as a result of ice formation and ice melting were revealed using the conservative isotopic parameter δ18O as a tracer. The amount of Atlantic, river, and melt water as well as the volumes of water withdrawn for ice formation are quantified for six water masses typical of the Laptev Sea. Both melt and transformed (as a result of ice formation) water types are present in the surface river water mass. The prevalence of melt water is observed in the range of sea water salinity from 0 to 7–8 psu. The maximum content of melt water in this salinity range can reach 40%, and the desalination resulting from ice melting reaches 0.2–0.7 psu. The areas with the maximum water removal for ice formation are linked to the position of summer and winter water of the Laptev Sea, in the area of the Anabar-Lena, East Taymyr, West New Siberian, and North New Siberian flaw polynyas and fast ice in the southeastern part of the sea. In these regions water removal for ice formation makes up 10 to 20% and is observed from the surface to the bottom even during the summer-autumn period. Atlantic water is characterized not only by mixing with river water from Siberian rivers but also by transformations resulting from ice formation. However, this effect is largely associated with the convective mixing with overlying layers where ice formation occurs. Mean temperature of the bottom layers of Arctic basin water is by 2.2°C lower than the mean temperature of Atlantic water, and mean salinity is by ~0.06 psu higher. In this water the presence of river water as well as the influence of ice formation and ice melting mass are less pronounced as compared to Atlantic water.

The “line” of hybrids recommended by the Ural Research Institute of Agriculture Ob 140 SV (FAO 140), Ross 130 MV (FAO 130) and Kuban 101 SV (later Kuban 102 SV) (FAO 120) in 2016…2020 occupied 81.8…90.6% in the structure of sown seeds in the Sverdlovsk region. The area under corn by 2014 increased to 19.39 thousand hectares (6.3 times compared to 2008) and in 2015…2020 it stabilized at the level of 19.3…21.0 thousand hectares. The production test of the “grain” corn cultivation technology developed by the Ural Research Institute of Agricultural Sciences was carried out in four basic farms, in which the area of corn sown increased by 1.9 times over the period from 2012 to 2020, with a simultaneous increase in the sowings of high-protein crops: alfalfa and oilseeds. In the agricultural organizations of the SEC “Kilachevsky” and the SEC named after. The starch content in the silo reached 202-364 g/kg in 2017…2020, in some years it decreased to 142…146 g/kg (SEC “Kilachevsky”) and to 64…67 g/kg (SEC im. Zhukov). Over the past 3…5 years, individual farms of the region have begun to harvest cornage from corn. In the SEC “Kilachevsky”, the starch content in the new type of feed was 247 g/kg SV in 2018, 341…407 g/kg in 2019 and 439 g/kg SV in 2020. The research was carried out on the basis of the FSBSI URFANITS UrB RAS as part of the State Task on the topic “Creation and improvement of adaptive technologies for the cultivation and processing of economically significant agricultural crops based on the optimization of biotic and abiotic factors”.

The authors present the determination method of nutrient’s background concentration in the seawater. In this work, as a basis for the proposed method, we use a three-component system [1-6, 10, 11, 12, 13] for mixing water masses in the Barents Sea based on the parameter δ18О. Simple mixing of purely Atlantic water masses and purely river water masses, as well as ice formation and melting processes, were taken into account. The authors suppose that the background concentration is a concentration that changes only as a result of water transformation, such as melting and freezing. The authors consider background concentration of phosphates, nitrates and silicates for the Barents Sea calculated from previously collected data. The difference between measured and background concentrations indicates the production or destruction process of organic matters. If the results are positive - there is destruction; if negative, there is - production. The data for δ18О, salinity, phosphates, nitrates, and silicates that were used in this study were taken from an open-source database published on the NASA website and in our own collection. Samples were taken in the summer.

When researching the mixing of two or more water masses and their subsequent transformation, ideally, the most conservative parameters are used. Since the 1970s, the isotopic parameter δ18O has been used in various oceanological research works for example: Ostlund and Hut (1984) [J. Geophys. Res., 89, 6373–6381] and many others. The use of the salinity value and δ18O allowed the construction of a three-component system (“classic”) of equations (TSC). Nevertheless, in the work: E.O. Dubinina and co-authors (2019) [Okeanologiya, No. 1, 57. 38-48. ] it was demonstrated that “the application of the three-component mixing to modified waters causes an overestimation of river water input”. A model of ‘mixing-modification’, which eliminated this drawback, was presented in the work and the difference of estimation with the three-component system may be up to 20%. In the present study are also shown that the classic three-component system is fully applicable only under the conditions of ice melting, and under the conditions of ice formation estimates based on the three-component system give overestimated results of basic waters content in the final water mass. However, the methodology of sea water component composition estimation in this work differs slightly from the methodology presented in the above publication. A modified three-component system (TSM) presented in this work allows elimination of such inaccuracies. The difference between average values for the available series of observations according to TSC and TSM increases in the following order: Kara Sea > Laptev Sea > Barents Sea and the maximum difference for Atlantic waters and river waters (30.5% and 25.2%, respectively) was observed for Laptev Sea; 17.6% and 9.5%, respectively, for the Barents Sea and 16.3% for both components of the Kara Sea. To reveal newly formed water masses, a method of cluster analysis was applied. The composition of basic waters in the final water masses of the seas in question was obtained, as well as the values of these waters modification during ice formation or ice melting. General regularities of water masses formations in the discussed seas are delineated. An illustration of the average values of these magnitudes in water masses (clusters) in the system of coordinates content of: Atlantic Waters – river water– ice water for each sea had similar character, but their magnitudes differed depending on the different magnitude of the river runoff and different extent of these waters’ modification during ice formation and ice melting. It is noteworthy that the value of “ice water” has an important scientific and practical significance, because it is used to summarise singular cycle values, and possibly, several observation cycles of ice formation while also being unique, maintaining the “memory” of the ice formation process values, which occurred in these waters.

In this work a new method of small density wood plates obtaining without adhesives use based on preliminary hydrodynamic processing of wood is offered. It has been established that this method allows to receive the plates with indexes of physicomechanical properties and water resistance surpassing the known analogs made with the use of synthetic adhesives.

In this paper, we consider the classical Burke–Schumann problem as applied to the construction of a mathematical model of a diffusion flame spreading over a fuel film deposited on a thin substrate. This formulation is used to model the combustion of a gaseous fuel flowing from a thin slot (half-width xin) and mixed with oxidizer flowing from a parallel slot (with the outer boundary xout). The key parameters determining the position of the flame front in the space are identified: the Peclet number Pe, the stoichiometric parameter A dependent on the equivalence ratio, and the geometric parameter Xin = xin/xout. The dependences of the flame length on these parameters, including xout →∞, are analyzed. Comparison shows good agreement between calculated and experimental data.

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals (ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of high-temperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature (up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas (LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases (LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

Modern society is already unthinkable without computer-aided design systems, which are systems that implement information technology for performing design functions. These technologies are actively used in all branches of human activity, including in medicine [5]. It is known that the use of an external fixation device makes it possible to cure complex cases of fractures of human pelvic bones [4,6]. To simplify the design, secure fastening, reduce trauma, various types of external and internal fixation devices are applied. Nowadays, treatment of complex fractures of human pelvic bones with the help of the fixing Ilizarov apparatus takes place on the basis of the facts of analyzing the patient’s condition, that is, by an empirical method. Eliminating modeling from the design calculation may aggravate the patient’s condition due to such factors as excess load on the frame or its insufficient rigidity.