Strongly intensive quantities for multiplicity and total transverse momentum are calculated using the multipomeron exchange approach for
pp
collisions in the range of SPS to LHC energies. The model ...allows for the interaction between quark–gluon strings, the role of which grows along with the energy of collisions. This approach is generalized to the case of
p
Pb collisions.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The purpose of the article is to summarize the calculation procedure and calculate the forest machines floatation depending on the type of mover and soil conditions. Research methods are analysis of ...literary sources, numerical methods of applied mathematics during calculations and calculated data approximation. Formulas and the procedure for calculating the track depth, the coefficients of resistance to movement, adhesion and traction of the forest machines movers are given. In the compiled mathematical model, slipping is not an input parameter; its value is determined by calculation comparing the resistance forces to movement and the mover adhesion to the bearing surface. According to the calculations results, it was found that forestry machines with a caterpillar mover have greater cross-country ability compared to wheeled vehicles. On weak and moderate soils, the bearing floatation loss of tracked vehicles due to insufficient mover adhesion to the bearing surface does not occur. A factor limiting the pressure of the caterpillar mover on the bearing surface should be recognized as the track depth, since at a pressure of more than 0.04 MPa, the track depth exceeds the machine clearance. To ensure the bearing floatation of wheeled vehicles on weak soils, the pressure of the wheeled mover should be limited to 0.6 MPa. To ensure the bearing floatation of wheeled vehicles on moderate soils, the pressure of the wheeled mover should be limited to 0.95 MPa.
The article aims at assessing relationships of deformation modulus, cohesion and angle of internal friction of various soil types with penetration resistance (cone index). Research methods include ...analysis of reference information, computational experiment and approximation of calculated data. The analysis is performed for calculated values of mechanical properties of coarse-grained sand, medium-grained sand, fine-grained sand, silty sand, sandy loam, loam and clayey soil. It is found out that angle of internal friction and cohesion of sandy soils, sandy loam, loam and clayey soil are related to deformation moduli by power dependences. Coefficients of the formulae depend on the soil type and, according to the results of calculated data processing, are invariant with respect to porosity coefficients and consistencies of the soils. It is shown that cone indices are related to deformation moduli by power dependences, the coefficients of which are determined by soil type and are invariant with respect to the porosity coefficients and consistencies. The obtained calculated values of the cone indices correspond well with reference data on the penetration resistance of mixed soils. The dependences intend to simplify procedure for estimating mechanical properties of the bearing surface, since, with a soil type known, using the value of deformation modulus or cone index, it becomes possible to calculate the soil parameters characterizing the shear resistance.
The purpose of this article is to investigate the relationship between the estimated values of nominal and average wheeled mover pressure on the ground and a rigid bearing surface. Research methods ...are mathematical analysis, computational experiment, and calculated data approximation. The article presents and compares methods of calculating average mover pressure in deformable soils, medium mover pressure on a rigid base, and nominal pressure on soil. According to the calculations results, it was found that the average mover pressure on firm soils almost corresponds to the estimate of the mover pressure on a rigid base. The nominal pressure is lower than the pressure on the rigid base by 40-50 kPa. The average pressure estimate on moderate soils is close to the nominal pressure. The average pressure on weak soils in the load range of 10-20 kN is close to the nominal pressure, at high values of wheel load the average pressure on the soils category is estimated to be twice less than the nominal pressure of the mover on the soils. It has been established by calculation that the average pressure of the wheeled mover on the deformable forest soils and on a rigid base is connected with the value of the mover nominal pressure on the soils, used by the foreign researchers. The dependences are linear and include correction factors, the values of which are determined by the mover parameters (wheel width and diameter, tyre pressure, and wheel load) and the forest soil category. The received equations allow simplifying the interaction estimates comparison process of forest machine movers on the soils, given within the domestic and foreign techniques limits.
Due to the presence of contradictory results about the effect of dopamine on the synthesis and secretion of thyroid hormones, as well as the absence of this information in clinically healthy ...individuals, we were interested in studying this problem in permanent residents of the Arctic territories, which are characterized by high thyroid activity and dopamine content. The aim of this work was to study the hormone levels of hypothalamic–pituitary–thyroid axis (HPTA) under the different levels of dopamine in the blood of permanent residents of the Arctic territories. Materials and Methods: We examined 316 healthy individuals (the indigenous population, mestizos, and the local Russian population) born and permanently residing in the territories of the Russian Arctic zone. The examined participants were divided into 3 groups: Group 1 with undetectable levels of dopamine in the blood (0 nmol/l); Group 2 with reference levels of dopamine (<0.653 nmol/l); and Group 3 with increased levels of dopamine (>0.653 nmol/l). The serum levels of TSH, T4, FT4, T3, and FT3 , and the plasma dopamine level were determined by enzyme immunoassay. The plasma cAMP level was determined by radioimmunoassay. Results: In individuals of Group 1, there was a decrease in the activity of hypothalamic–pituitary–thyroid axis (HTPA) and the peripheral conversion of iodothyronines compared with persons with reference or increased dopamine levels. In individuals of Groups 2 and 3, we found an increase in the activity of HTPA with an increase in the blood level of dopamine. The absence of the inhibitory effect of high levels of dopamine on HPTA hormones in the examined individuals may be a compensatory-adaptive response of the body under the conditions of permanently acting extreme factors of the North.
Abstract
When performing energy-intensive work in forestry related to the processing of stumpy soil, it is necessary to substantiate new requirements for forestry tractors in terms of weight, energy ...and dynamic parameters. Their change will cause a change in the disturbing forces acting on the transmission shafts of the unit, which can excite torsional vibrations in its dynamic system. When the natural frequencies of the oscillations coincide with the disturbing ones, unwanted resonant oscillations may occur. The most common models for studying dynamic properties are models in the form of complex multi-mass torsional dynamical systems. To calculate the vibrations of torsional systems, an algorithm and a program for solving a system of differential equations were drawn up. Their solution made it possible to calculate the amplitude-frequency characteristics (AFC) of the dynamic systems of tractor units. The allocation of zones of forced oscillations in transmissions from the working bodies on the frequency response, as well as the coordination of the parameters of the working bodies with the parameters of the transmissions is a necessary condition for ensuring the effective operation of forestry units. When changing the moments of inertia of rotating masses, it is necessary to analyze the vibrations that occur in branched transmissions with active working bodies with significant moments of inertia. To determine their optimal parameters, the presented mathematical models can be used.
The article presents traditional ecological knowledge of natural cryogenic resources (ice, snow, permafrost, etc.) for food preservation used by indigenous people, living in the Yamalo-Nenets ...Autonomous Okrug of Western Siberia. On the basis of ethnoecological approach and original fieldwork research, we analysed the construction of different types of storages for fish ("lednik", ice cellar, "snezhnik", and "merzlotnik"). As a result, we offered to adapt traditional ecological knowledge of indigenous people, living in the Arctic zone of Western Siberia, to developing new energy saving and eco-friendly technologies for preservation and transportation of fish, which could effectively use specifics of cryogenic conditions of the Arctic region.
Multiparticle production in soft hadronic interactions can be successfully described in the framework of the color-string approach, which will probably be derived from the first principles of ...chromodynamics in the future. A fundamental property of this approach is the translation invariance of the rapidity spectrum of charged particles produced by one source at high energies. This symmetry results in the appearance of long-range rapidity correlations through event-by-event fluctuations of the number and/or type of strings. We describe the behavior of correlations between multiplicities (
n–n
) and between the transverse momentum and multiplicities (
pt–n
) of charged particles with the mechanism of forming sources of two types taken into account. We obtain an exact analytic expression for the (
n–n
)-correlation coefficient. Because no exact solution can be obtained for the (
pt–n
)-correlation coefficient, we propose an effective approximation that significantly simplifies numerical computations. We verify all these results by direct simulation using the Monte Carlo method. We also investigate how the fusion mechanism influences the behavior of strongly intensive variables characterizing the multiplicity fluctuations in two rapidity windows.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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