Home – Home – Jornals – Journal of Mining Sciences 2017 number 2

This paper presents a numerical study of the combustion of a hydrogen-air mixture in a model ramjet combustor with separate hydrogen and air supply during activation of O₂ molecules with resonance laser radiation at a wavelength of 762.3 nm and 193.3 nm. The calculation is made using the parabolic Navier-Stokes equations taking into account chemical transformations, laser irradiation, and the unevenness of the air parameters at the combustor inlet due to the complex gas-dynamic structure of the flow in the air intake. It is shown that the combustion efficiency at the combustor outlet can be increased a factor of 2.8 by redistributing the hydrogen supply through the system of fuel tank pylons. Further increase in the combustion efficiency can be achieved by exposure of a narrow flow region to resonant laser radiation, more effectively at a wavelength of 193.3 nm. The combination of laser exposure together with the hydrogen supply redistribution increases the combustion efficiency by a factor of more than 4.7 compared to the base case. Furthermore, this provides a 95% increase in the axial force component in the inner portion of the engine flow path, which provides a positive contribution to the thrust. Estimation of the energy efficiency due to the use of laser radiation shows that the laser energy input required to achieve this effect is 40-80 times (depending on the fuel supply method) less than the increase in the chemical energy (compared to the case of no laser exposure) released due to fuel combustion.

The effect of a focused pulsed-periodic beam of a CO₂ laser on initiation and evolution of combustion in subsonic and supersonic flows of homogeneous fuel-air mixtures (H₂ + air and CH₄ + air) is experimentally studied. The beam generated by the CO₂ laser propagates across the flow and is focused by a lens at the jet axis. The flow structure is determined by a schlieren device with a slot and a plane sheet aligned in the streamwise direction. The image is recorded by a high-speed camera with an exposure time of 1.5 s and a frame frequency of 1000 s^-1. The structure of the combustion region is studied by an example of inherent luminescence of the flame at the wavelengths of OH and CH radicals. The distribution of the emission intensity of the mixture components in the optical discharge region is investigated in the present experiments by methods of emission spectroscopy.

The need to find reactive additives capable of reducing the combustibility of dimethyl ether is an important problem in connection with the widening use of ether as an environmentally friendly alternative motor fuel. In this study, the autoignition chemistry of mixtures of dimethyl ether with air in the presence of atomic iron was investigated by numerical methods. Atomic iron, which is an effective inhibitor of premixed laminar hydrocarbon flame was found to shorten the induction period. However, the additive affects only the first stage of the induction period. The mechanism promoting the low-temperature oxidation of dimethyl ether- air mixture by atomic iron involves the formation of hydroxyls in reactions involving iron compounds. Since the additive hardly changes the duration of the second stage of the induction period, it can be suggested that OH radicals play an insignificant role in the low-temperature oxidation of dimethyl ether at this stage.

The effects of silane temperature and ambient moisture on the ignition behavior are considered. The critical velocity for delayed ignition is determined for different silane temperatures and moisture contents in ambient air. The logarithm of the critical exit velocity is found to be inversely proportional to silane temperature. It is also observed that moisture in air has a strong inhibiting effect on silane autoignition in air. From a safety perspective, it is concluded that prompt ignition of silane is favored in a high-temperature and low-humidity environment.

This paper describes an experimental setup and method for determining the combustion completeness of the gas and condensed phases of gasification products of energetic boron-containing condensed formulations in high-enthalpy subsonic air flow. The results of investigation of the combustion of a two-phase fuel mixture in a channel of constant cross section at various temperatures, pressures, and component ratios are given. The combustion regularities of a boron-containing condensed phase in a high-enthalpy air flow are identified. The obtained data can be useful in computational and experimental studies of operation processes in power plants.

A performance analysis and experimental study of a hybrid gas generator to be used in a ducted rocket are presented. Such a system exhibits potential advantages with regard to safety, performance, costs, availability of the fuel components, storability, and thrust control. A combination of a paraffin wax fuel and oxygen in the gas generator ensures a high regression rate and reveals oxidizer-to-fuel ratios as low as 0.14 in the gas generator (compared to the stoichiometric ratio of 3.4). A fuel regression rate correlation versus the oxidizer mass flux is derived, presenting a major advantage for the fuel flow rate management in comparison to control of the solid propellant gas generator burning rate through the pressure exponent, which requires mechanical interference with the hot nozzle flow to ensure a change in the combustor pressure and a corresponding change in the burning rate. Evaluation of the ducted rocket (with different oxidizers) versus pure ramjet performance shows a higher specific thrust for the former, though the latter exhibits a higher specific impulse.

A cylindrical shock wave in a dusty gas under the action of monochromatic radiation into the stellar atmosphere with a constant intensity per unit area is discussed. The gas is assumed to be grey and opaque, and the shock is assumed to be transparent. The dusty gas is considered as a mixture of a non-ideal gas and small solid particles. To obtain some essential features of shock propagation, small solid particles are considered as a pseudo-fluid, and it is assumed that the equilibrium flow condition is maintained in the entire flowfield. The effects of the parameters of the gas non-idealness, the mass concentration of solid particles in the mixture, the ratio of the density of solid particles to the initial density of the gas, and the radiation parameter on flow variables are investigated. It is shown that an increase in the gas non-idealness and the radiation parameter has a decaying effect on the shock waves, whereas the shock strength increases with an increase in the ratio of the density of solid particles to the initial density of the gas. It is found that an increase in the gas non-idealness and the ratio of the density of solid particles to the initial density of the gas has the opposite effects on the fluid velocity, pressure, and shock strength. It is also shown that an increase in the radiation parameter has a trend to decrease the flow variables and the shock strength.

This paper presents the results of experiments to study the shock compression of samples of vanadium deuterides and hydrides of the following compositions: VX_0.51, VX_0.7-0.9 and VX _≥1.6, wher X is H or D. The experiments were carried out in a pressure range of 20-140 GPa. The technology of synthesizing samples using electrolytic vanadium containing not less than 99.7% of the basic substance. The shock adiabats of vanadium deuterides and hydrides were determined using the well-known reflection method. The samples were compressed using shock-wave generators based on the use of explosive charges of different power. The obtained experimental data are described by the equation of state developed using a model in which the specific heat and Gruneisen ratios of ions and electrons are functions of density and temperature. At low temperature, the specific heat changes in accordance with the Debye theory. The removal of the degeneracy of the electron gas at higher temperatures is considered. The influence of ionization processes on the thermodynamic functions is effectively taken into account.

This paper reports the synthesis, experimental and theoretical studies of a novel inorganic-organic cocrystal energetic material: methylamine triethylenediamine triperchlorate (MT). MT is synthesized by a rapid “one-pot” method. The performance test of MT shows that it is more powerful and has lower sensitivity in comparison to the benchmark energetic material, i.e., 2,4,6-trinitrotoluen (TNT). The molecular and crystal structures of MT are determined by means of x-ray diffraction (XRD). The compound crystallizes in a monoclinic system (space group Pn) with cell dimensions a = 8.975(18), b = 17.836(4), and c = 10.455(2) Å. The band structure and the density of states are calculated by an abbreviated form of the CASTEP code. The first principle tight-binding method within the general gradient approximation is used to study the electronic band structure, density of states, and Fermi energy. The results indicate that the main mechanism of cocrystallization originates from the Cl-O^…H hydrogen bonding between - ClO₄ and -NH₂.

Coal particles when subjected to shock waves can undergo rapid fragmentation, pyrolysis, and combustion, causing enhanced process intensity and efficiency. Particle fragmentation plays a crucial role in this process. Exposure of coal particles to a shock wave is modelled in the present work as combined convection and radiation at the surface and conduction in the interior. Local temperatures within a coal particle and the corresponding thermal stresses are computed to study particle failure. Particle fracture is modelled by a three-parameter Weibull probability to predict the failure location and time. Simulations indicate that pulverized coal of size up to 250 μm subjected to a shock wave for varying operational, thermal, and physical parameters can experience initial failure within 150 μs. Particles of size d ≥50 μm or higher wave strengths (with Mach numbers M ≥5) mostly trigger exfoliation, while interior fragmentation dominates at smaller sizes (d ≤ 25 μm). An initial fracture study reveals that pulverized coal with predominant sizes d ≤ 100 μm and the coal rank from lignite to bituminous coal is potentially suitable for detonation combustion in waves at Mach numbers M = 3-6. Coal particles under continuous exposure to post-shock conditions undergo recursive exfoliation until the core is 20-40 μm, after which an interior fragmentation phase is seen until the core is about 1-3 μm. Much finer coal particles, of the order of internal fragmenting cores, are hardly fractured due to low thermal stresses caused by rapid uniform heating. The fracture model approach for studying shock-induced combustion is validated by a reasonable match of the computed ignition delay with experiments. The fragmentation history indicates a substantial increase in the particle surface area and temperature under shock exposure, as against conventional combustion, leading to an increased order of the burning rates at the onset of ignition, which can sustain through the entire burning phase.

This paper presents the results of numerical analysis of a viscoplastic model of the formation of hot spots based on the solid-phase mechanism of hot-spot ignition of an energetic porous material under shock-wave loading. The highly viscous pore collapse is considered, which is of great interest in the theoretical study of shock-wave initiation of heterogeneous energetic materials. Interphase heat transfer was described under the assumption that the gas is ideal and hence the uniform pressure condition can be used. Parametric analysis was conducted, and the specific features of the effect of heat transfer and interphase heat transfer on the critical conditions of shock-wave initiation of chemical reaction in the energetic porous material were determined.

Reactive materials are a new class of energetic materials that extremely and efficiently release energy under the influence of high impact loading. An impact tester is used in the present study to explore the impact ignition characteristics of Al/PTFE reactive materials and the impact ignition pressure of Al/PTFE reaction materials under different conditions. The experimental result shows that the critical ignition pressure is approximately 1.44 GPa. Meanwhile, it also shows that the material compactness has a much less pronounced effect on the impact ignition pressure for this reactive material if the loading time scales are of the order of several milliseconds. Plastic work and viscous heat both play a significant role in impact ignition. Finally, it is shown that impact ignition ensures a higher energy release rate than surface ignition.

The spectral-kinetic characteristics of luminescence of PETN with iron nanoparticle inclusions are measured in real time under laser initiation of an explosion (wavelength is 1064 nm, and pulse duration is 14 ns). During the action of the laser radiation pulse, the luminescence of the samples is observed, and explosive decomposition occurs in a microsecond time interval. The spectral pyrometry method is used to establish the thermal nature of explosive luminescence. The explosion temperature is estimated to be 3400±100 K.

The detonation velocities close to ideal velocity relative to large charges of highly dispersed ammonium perchlorate (APC) and its mixtures with different explosive substances in thick-walled steel pipes are measured. The relationship of the detonation velocity of APC with its density and the relationship between the detonation velocity of mixtures with the correlation of components and oxygen coefficient of the mixtures are determined. The calculation of the detonation velocity of APC/explosive/Al three-component compositions is proposed for the first time.

This paper describes the results of the experimental study on the effect of structural parameters, such as diameter, height, and density, on the development of explosive transformation of an NCP energy-intensive metal complex during bridge initiation. The results are compared with those obtained in shock-wave initiation.

In this paper, the commercial finite element code LS-DYNA is employed to simulate the process of a certain kind of a linear shaped charge jet penetrating into a TC4 (Ti-6Al-4V) titanium alloy plate of moderate thickness. The fracture profiles agree well with experimental observations, which confirms the validity of the code and the Johnson-Cook material model applied to describe the TC4 plate. The fracture pattern of the plate is drawn based on this comparison.

For theoretical description of interaction between geomechanical and physicochemical processes in multiphase coal seams, the author for the first time proves the existence of an analytic “extension” of the operator connecting Langmuir’s equation and the kinematic expression for pendulum waves in high- stress geomedia of hierarchical block structure.

The first results of the experiments on influence of fluid injection on the mode of interblock contact deformation are reported. It is found that deformation energy consumed to radiate seismic waves largely depends on parameters of fluid injected in fracture. Dilatant fluid appears to be the most efficient in the decrease of the seismic energy as the fluid viscosity grows with the rate of deformation. In the laboratory test, the slip-stick motion mode transforms into the quasi-stable creep in a single deformation cycle after fluid injection.

A new approach to local rockburst hazard problems and rockburst prediction is demonstrated in terms of acoustic measurements in two mine workings of Joint Kirov Mine, Apatit. The new approach is based on spectrum-correlation analysis of acoustic emission signals, on the one hand, and on the Griffith-Irwin fracture model, on the other hand. Acoustic emission signals are recorded using new-generation portable system Prognoz-L for local rockburst hazard monitoring. Prognoz-L provides digital recording and processing of a wide range of acoustic signal parameters. The analysis of spectrum parameters of the recorded signals confirms applicability of the innovative software/hardware system to predict dynamic events in rock masses.

The author studies stability of a structure (platform) on a pile foundation using physical modeling. Disturbing force is applied by a pendulum generating seismic impulse vibrations. The data on measured displacements of two points on the platform surface are used to find the platform incline under varied number of blows, blow energy, distance to the blow point and the platform weight.

The formulas and schemes are presented to determine the length of charges and their inert gaps. The calculations are based on the theory of superposition of seismic waves under blasting in rock mass. The proposed procedure enables calculating parameters of distributed charges under any ground and geotechnical conditions of blasting ensuring quality fragmentation, elimination of flyrock and reduction in drilling operations.

For the selective disintegration of kimberlite and dissociation of diamond crystals of undisturbed natural integrity, the authors have designed a tool with cutters having hardness lower than diamonds but higher than binding minerals in kimberlite. The article gives the results of testing the prototype of the heterogeneous material disintegrator on soft kimberlite extracted from Manchary pipe. The prototype includes disc brushes made of high-strength steel wire. The selective disintegration prototype is a preproduction model of lab, semi-commercial and commercial disintegrators. The method is applicable to recover hard particles from geological samples.

The researchers analyze energy processes running in an autonomous electric power system consisting of a synchronous permanent magnet generator and a semiconductor electrical energy converter. Current, voltage and capacity of key components of the system are evaluated, and the system operation modes are determined for the variable magnitude and character of applied load at the constant voltage output frequency. Parametrical law is proposed to control semiconductor converter serially connected to load and generating reactive power. The influence of the converter on the basic design parameters, energy specifications of the synchronous generator and the system as a whole are evaluated.

The authors identify some factors that govern energy input of borings removal from hole bottom to an unloading point using auger drilling string assembly. Of specific significance appears to be the factor of insufficient reliability of anchor gears and centering devices of the drilling string assembly, which makes continuous drilling impossible without permanent servicing. The article gives the analysis of bench testing data of bearings with antifriction filler for drilling string mounting groups to be serviced outside the areas of drill holes. The design solutions based on the investigation results and aimed to improve reliability of anchor gears and centering devices of an auger drilling string assembly are described.

New results that solve the important scientific task of providing electrical networks with an isolated neutral voltage up to 1000 V in mining enterprises are obtained. The method for measuring the admittance of insulation networks with isolated neutral voltages up to 1000 V, which will provide improved accuracy and speed measurement admittance network insulation, is described. The measurement is made by adjusting the additional conductance to ensure equal quantities of module phase voltage to earth and zero phase-sequence voltage. In this connection the additional conductance corresponds to the admittance of network. The simulation model of a method of measuring the admittance of insulation using the Matlab/Simulink environment is analyzed. The proposed method is simple, as the instrumentation, single-phase voltage transformers that are needed to measure the admittance of network, are in the service manual of the energy management companies.

The author analyzes the method to prevent gas-dynamic events during mechanized mining of karnallite at Upper Kama potassium-magnesium salt deposit. The method ensures efficient gas drainage and relaxation of outburst-hazardous rocks due to a horizontal drainage borehole slotter in the sidewall of a face entry. The data of the mine experimental studies are presented. The time behavior of residual gas content and air sorption indexes of karnallite in the influence zone of the drainage borehole slotter is determined. It has been found expedient to use borehole slotting to prevent gas-dynamic events during mechanized mining of karnallite.

Under discussion are the direct dumping flowsheets applied to remove lower overburden layers at coal series deposits in Kuzbass. The authors present the calculation procedure for the parameters of overburden excavation and re-excavation flowsheets using draglines. It is found how the re-excavation coefficient depends on the place and level of the dragline site. The recommendations on selecting the dragline route in internal dumping are made. The main trends toward expanding the area of application of the direct dumping technology are identified.

The author proposes a promising technology to separate monolith stones and preformed blocks for construction from rocks mass using a diamond rope cutting machine ensuring reduction in labor content, cost and loss as well as enhancing the process production output. The analytical model is developed, and the dependences between the material loss and the technology parameters are found. The main standards are formulated for the technology, and the ways of improving the diamond rope cutting machines design based on material loss minimization are specified.

It has been found that the rated and actual data on methane emission in production headings in some Kuzbass mines disagree. The air and gas control shows that actual methane emission from broken coal is much less than the rated data when a coal shearer has high advance velocity and production output. The authors demonstrate the connection between an average diameter of broken coal fragment, shearer advance velocity and drum rotation speed using Darcy’s law of flow and Langmuir’s adsorption equation. It is found that methane emission from broken coal and natural coalbed methane content relate nonlinearly and that the relationship of absolute methane emission, shear advance velocity and production output has an extremum.

The article gives new experimental data on chemistry, phase composition, structure and physicochemical properties of surface of minerals composing metasomatically altered kimberlite rocks. The authors have determined formation conditions and basic genetic types of mineral micro- and nano-size phases on diamond surface in the form of aluminosilicate minerals, thin coats of clayey minerals, calcite and dolomite bound with carbonate cement, as well as their negative effect on recovery of diamonds by foam separation. The mechanisms and efficient methods of combined energy effects on the natural heterogeneous system of diamond and surface mineral phase are found to rupture hydrophilic mineral films on diamond surface, prevent their repeated formation and reduce diamond loss in processing of diamond-bearing kimberlites.

This paper deals with the management of Mediterranean Planted Conifer Forests (MPCF), dominated by the aleppo pine Pinus halepensis and the potential for using natural regeneration as a basis for transformation of simply structured even-aged and mono crops plantations into mixed forest. We studied the variation along a rainfall gradient, in the natural regeneration of tree species. The study was conducted in four forests located within the Mediterranean zone of Israel, which extends from the semiarid northern Negev desert (rainfall ca. 300 mm per year) in the south to the humid central region close the coast line (ca 550 mm per year). Standing trees measurements including mean tree height, diameter at breast height, crown width, canopy cover, stand density of the mature strata and the number of saplings and their species composition along with the landscape characteristics (slope, aspect, percentage of rock cover and forest floor light regime) have been performed at randomly established 200 m² area circular plots. Although a water supply is the main limiting resource for forest growth and productivity, so far no significant relationship between the quantity of regeneration and precipitation could be found. Strong linear correlation between the number of the mature trees and pine’s regeneration have been revealed and the detailed management plan of how to support a natural regeneration using a principal of Continues Cover Forestry was suggested for MPCF, including a recommendation for intensity and time of thinning.

The forests of Northern Kyrgyzstan are distinguished by poor species composition. Severe forest growing conditions, dry climate, vertical zoning, exposition of forests to the northern slopes, while the opposite slopes are treeless created a more or less tolerable conditions for the existence of only one species - Tien Shan spruce Picea schrenkiana Fisch. et Mey . Increase of productivity and stability, as well as strengthening protective properties of the spruce forests of Northern Kyrgyzstan is possible by the introduction of a tree species growing in other areas. For more than 80-year period in the region have been introduced about 120 different species of coniferous and deciduous trees. Many of them have second stage of introduction, noted by good growth, fruiting, and in some cases regeneration. The article summarizes the introduction of 83 years old Scots pine forest plantations in Northern Kyrgyzstan, growing in a variety of forest conditions. Forest inventory characteristic and an analysis of the growth in stem diameter is done. There is an estimation of the viability and prospects for the species in local conditions. Phenological observations completed. Regeneration of Scots pine and Tien Shan spruce in forest crops and out of its boundaries have been studied, which can lead to a species’ change in future. Pine in local conditions starts to occupy areas with severe forest growing conditions, and this confirms that the specie is acclimatized well and able to occupy areas, where Tien-Shan spruce can’t grow due to its bio-ecological features.

The microevolution theory can serve as the theoretical foundation of forest seed zoning and of the population introduction, the subdivision of Pinus sylvestris range in Russia into 10 phylogenogeographical regions - as their genetic-geographical base and climatologic-geographical regularities of the acclimatization of the introduced crops - as the ecological base. As a result of regressive analysis of Pinus sylvestris provenance crops parameters in Russian Plain forest-steppe is was determined the authentic decrease of the parameters of their survival and stands production, according to the increase of gradients of climate limiting factors - duration of vegetative period and photoperiod - between sites of origin and introduction of populations both along of the submeridional transect and of the longitudinal ones. Thus, the hypothesis about the greater adaptivity of the local plant populations by comparison with introduced ones and the correctness of the principle of «climatic topoanalogues» in the acclimatization were confirmed on the quantitative factorial-climatological level. The total net of geographical coordinates and of corresponding elementary forest seed regions measuring 1° in latitude and 5° in longitude formed by it was suggested as the ordination matrix of forest seed zoning within the P. sylvestris areal. The parameters of seed transfer reglamentation in latitude, longtitude and altitude were suggested on the connections base of survival and stands production of introduced Scots pine crops with climatic gradients. These principles can serve as a genetic-climatologic-geographical base for the development of the theory of plants acclimatization and of regional and federal seeds zoning of Scots pine forests for their crops, selection and hybridization.

Differentiation of 83 Scots pine climatypes by height growth at the age of 37 years in the provenance trial was done. Three groups of climatypes were distinguished as: fast-growing, moderate-growing and slow-growing. The research at the age of 20-25 revealed 13 climatypes of 27 from the fast-growing group as candidates to breed-populations. These climatypes are from Krasnoyarsk Krai, Irkutsk Oblast, Kemerovo Oblast, Murmansk Oblast, Karelia, and the Republic of Komi. At the age of 37 years they confirm the status of perspective climatypes in height growth, survival, and resistance to fungal pathogens as it was noted earlier (Kuzmina, Kuzmin, 2007, 2008). The average height of trees of these climatypes exceeds control height by 32 %. The moderate-growing group consists of 18 climatypes, five of them are candidates to breed-populations. The intensity of their growth was reduced but average height is at the level of control average value. The third group has the largest number of climatypes. After the inventory in 2013 two climatypes previously marked as perspective were added into the third group. Last years the intensity of their growth was significantly reduced because of disease caused by cenangium dieback at the 22-24 years old. So the rank status of studied climatypes in different age periods is significantly changeable because of different reaction to ecological factors. The analysis of annual height increments growth confirms that objective conclusions about selection of perspective climatypes could be possible only after 25 years old of pine.

The structure of pine forests in various natural areas of European Russia depends on environmental conditions, specifics of soil and underlying parent rock. Types of pine forests are distinguished by such features as their species composition of the lower layers, structure of grass-shrub layer and the nature of its mosaic. The purpose of the study are regional features of the composite pine forests, distributed on ancient terraces of left bank of the Volga River in north-western Tatarstan, considering specifics of their position in the contact zone of coniferous-deciduous forests with steppes. The structure of the communities of the pine forests on such indicators as species richness, quantitative participation of species, their occurrence and horizontal structure of grass cover were analyzed, and detailed description of the stand and of its renewal was given. In addition, ecological and coenotic structure of communities of pine forests was investigated. It was found that group of types of composite pine forests on the slopes and flat sections of high Volga terraces in northwest of Tatarstan are distinguished by age and completeness of the stand, but is characterized by similar composition of dominant species of lower layer and microgroups in grass layer composition. These communities are characterized by high participation of meadow-steppe plants. This feature distinguishes them from composite pine forests that are found in the central part of the European Russia. This is due to the fact that the area of our study takes position of a buffer, with broad invasion of meadow and meadow-steppe species in the communities of pine forests, especially when anthropogenic disturbances take place. The probability of further transformation of pine stands in the direction of their xerophytization has been identified.

Wildland fires distribute unevenly in time and over area under the influence of weather and other factors. It is unfeasible to air patrol the whole forest area daily during a fire season as well as to keep all fire suppression forces constantly alert. Daily work and preparedness of forest fire protection services is regulated by the level of fire danger according to weather conditions (Nesterov’s index. PV-1 index), fire hazard class (Melekhov’s scale), regional scales (earlier called local scales). Unfortunately, there is still no unified comparable technique of making regional scales. As a result, it is difficult to maneuver forest fire protection resources, since the techniques currently used are not approved and not tested for their performance. They give fire danger rating incomparable even for neighboring regions. The paper analyzes the state-of-the-art in Russia and abroad. It is stated the irony is that with factors of fire danger measured quantitatively, the fire danger itself as a function has no quantitative expression. Thus, selection of an absolute criteria is of high importance for improvement of daily fire danger rating. On the example of the Chunsky forest ranger station (Krasnoyarsk Krai), an improved technique is suggested of making comparable local scales of forest fire danger rating based on an absolute criterion of fire danger rating - a probable density of active fires per million ha. A method and an algorithm are described of automatized local scales of fire danger that should facilitate effective creation of similar scales for any forest ranger station or aviation regional office using a database on forest fires and weather conditions. The information system of distant monitoring by Federal Forestry Agency of Russia is analyzed for its application in making local scales. To supplement the existing weather station net it is suggested that automatic compact weather stations or, if the latter is not possible, simple weather observation points should be organized in forest ranger stations and aviation bases for obtaining up-to-date weather information.

The study of tree-ring cell structure changes as the result of tree adaptation to varying environmental conditions becomes increasingly important to predict future vegetation shifts under projected climate changes. The estimate of intrapopulation annual variability of wood anatomy characteristics is particularly informative. It helps to divide the contribution of different ecological factors to total features dispersion. In this work, a comparative analysis of individual and climatic variability of tree ring structure characteristics of Gmelin’s larch Larix gmelinii (Rupr.) growth within northernmost forest was carried out. The trees from forest-tundra boundary has greater radial growth intensity, forms the bigger conductive zone in rings with wider mean lumen area in comparison with trees from closed forest. This result can be explained by adaptive features and height ecological xylem plasticity of larch. The tree rings structure of larch from boundary with tundra is determined by largely current weather conditions. Is because these ones evince high adaptive plasticity on the level of xylem structure. The xylem reflects joint changes of climate factors and local ecological conditions. The trees from closed forest are characterized by larger individual variability. The local conditions in oldest forest (for example, bad hydrothermal soil conditions) inhibit the radial growth and sensitivity to environmental factors. In this case, the trees on individual level are tended to save the normal functioning of water-transport system. The significant differences in ratio individual to climate variability of tree ring structure characteristics can be caused by the different in the level of ecological habitat heterogeneity or the different in the level genetic within-population heterogeneity.

The data on carbon stock and its distribution on the main pools in the ecosystem are presented for mature pine forest bilberry type in the middle taiga. The ecosystem of mature pine forest bilberry type concentrates 158.2 t C ha^-1. Upper 1 m soil layer contribute 53 %, phytomass - 44, coarse woody debris - 3 % to total carbon stock. Net primary production is determined. Input of stand is 70 %, ground cover - 30 %. It is found active accumulation of wood. It forms about 36 % of biomass production. Litter fall and it distribution on separate fraction are characterized. Litter fall ranged from 1.13 to 1.53 t C ha^-1. It is equal 3-5 % of forest floor mass. The tree plants are generating the most part of litter weight. Needless and leaves play the key role in litter of stand. Inactive fraction (branches, cones) are characterized by big inter-annual variation in litter fall production due to changing weather conditions during study period. Dynamic soil temperature is described on lower boundary of forest floor. We estimate that during growing season carbon flux from soil surface is 2.28-3.21 t С ha^-1.

Identifying the best practices of responsible and sustainable forest use is an important aspect for possible learning of experience and replication of the most interesting examples in forestry. Qualitative and timely reforestation of disturbed areas with economically valuable species is the key indicator for the performance of effective forest management. Conservation of rare species of plants and animals in the logged areas is not less important factor. Today the priority is given to natural forest regeneration because it provides the best opportunity to avoid unreasonable financial costs and, as a rule, is more resilient against various natural and anthropogenic factors. The article discusses various examples and logging types in secondary forests in the Tomsk and Omsk Oblast, which allow increasing the economic, environmental, and social importance of forests. On specific examples it is shown that the principle of non-interference in the green zones of settlements is erroneous and may lead to undesirable consequences. The rejection of logging in these stands, as a rule, leads to increases of the fire danger, growth of phyto- and entomological threats, the reduction of recreational appeal, etc. The use of partial logging methods suggested in the papers has allowed solving some of these problems.

Forest litter is one of the major carbon flow and main source for long-term carbon accumulation in forest ecosystems. Wild fires is a frequent and powerful event destroys fluxes of matter and carbon accumulation. In the article the first data of stationary investigation of litter fall in flow and its organic matter content in larch forest (Larix gmelinii (Rupr.) Rupr.) are presented. The study is conducted on Tukuringra range in Upper Priamurie (Amur Oblast, Russia) in the forest stand recovering after fire of 2003 year. Results shows that net annual inflow of forest above ground litter fall from all vegetation in burned forest is 2.8 times lower than in background forest. Grass litter fall and other tree debris (bark, seeds, cones, etc.) are main sources for annual litter fall input in burned forest. Litter fall composition in the burned forest is significantly changed and high variation of mass of litter fall fractions is observed. Accumulation of carbon and nitrogen is higher in majority of litter fall fractions in burned forest as compared to control one. Annual carbon input from litter fall is 164 gm^-2 in control forest and 76 gm^-2 in burned forest, total amount of nitrogen derived by litter fall is 1.7 and 2.4 gm^-2 for control and burned forest respectively. Our findings suggest that carbon accumulation processes in fire-prone boreal forests changed significantly. The research results can be used for modeling of carbon balance in taiga forest damaged by fire.