scholarly journals Increase in the efficiency of water transport of bulk mineral cargo by the segregation of feedstock at the initial technological stage

2021 ◽  
Vol 326 ◽  
pp. 00021
Author(s):  
Yuriy Lyashenko ◽  
Elena Menshenina ◽  
Elena Revyakina
Keyword(s):  
Water Transport ◽  
Production Cost ◽  
Building Materials ◽  
Slope Angle ◽  
Rolling Speed ◽  
Geometrical Parameters ◽  
Production Parameters ◽  
Technological Stage ◽  
Reduce Energy Consumption ◽  
The Difference

The paper gives the analysis of the volume of transportation of bulk mineral cargoes by water transport. It is established that the problem of the use of technological processes for sorting non-metallic building materials and coals transported by water transport is relevant. It is revealed that in the applied beneficiation system of crushed stone it is possible to reduce energy consumption due to the segregation of material into commercial fractions at the crushing stage by combining operations. The developed design of the receiving - segregation hopper is considered which allows classifying the feedstock at the initial technological stage of the production of crushed sandstone. A patented design of a segregation hopper and a technological scheme with its use are described. The volume of material sent to the crushing process is reduced by up to 50% due to the separation of particles of commercial fractions, which helps to reduce the production cost of a unit of the finished product. The principle of operation of the hopper is based on the difference in the rolling speed of particles of various sizes. The influence of the geometrical parameters of the chute and the size of the initial material on the capacity of the hopper is investigated. The influence of the slope angle of the chute and the particle size on the production parameters of the installation is proved. The configuration at which the drain wall achieves the highest throughput is determined.

scholarly journals Numerical Network Modeling of Heat and Moisture Transfer through Capillary-Porous Building Materials

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1819
Author(s):  
Borys Basok ◽  
Borys Davydenko ◽  
Anatoliy M. Pavlenko
Keyword(s):  
Building Materials ◽  
Moisture Transfer ◽  
Three Dimensional ◽  
Total Pore Volume ◽  
Equivalent Diameter ◽  
Average Pore ◽  
The Difference ◽  
Three Dimensional Coordinate ◽  
Solid Liquid ◽  
Heat And Moisture

The article presents the modeling of the dynamics of the vapor-gas mixture and heat and mass transfer (sorption-desorption) in the capillary structure of the porous medium. This approach is underpinned by the fact that the porous structure is represented by a system of linear microchannels oriented along the axes of a three-dimensional coordinate system. The equivalent diameter of these channels corresponds to the average pore diameter, and the ratio of the total pore volume to the volume of the entire porous material corresponds to its porosity. The entire channel area is modeled by a set of cubic elements with a certain humidity, moisture content, pressure and temperature. A simulation is carried out taking into account the difference in temperatures of each of the phases: solid, liquid and gas.

Theoretical study on photoemission of double-layer AlxGa1−xAs/GaAs nanocone array photocathode

2021 ◽  
Author(s):  
Yan Sun ◽  
Lei Liu ◽  
Zhisheng Lv ◽  
Xingyue Zhangyang ◽  
Feifei Lu ◽  
...  
Keyword(s):  
Cross Section ◽  
Light Trapping ◽  
Spectral Response ◽  
Circular Cross Section ◽  
Geometrical Parameters ◽  
Internal Electric Field ◽  
Surface Emission ◽  
The Difference ◽  
Section Structure ◽  
Light Capture

In the design of photocathode, the internal electric field could be formed due to the graded Al compositional [Formula: see text] nanostructure, which can improve the top surface emission probability of carriers. In this paper, [Formula: see text] nanostructure array photocathode composed of two sub-layers is presented. Based on the finite element method, the influence of graded geometrical parameters on their optoelectronic characteristics is investigated. The results show that when the thickness of the sublayer is equal, the difference of the Al composition between the two sublayers of nanostructure is larger, the sub-layers are less, and the quantum efficiency is higher. The light capture ability of the photocathode can be enhanced by increasing the thickness and the array spacing of the first sublayer. Compared with the hexagonal cross-section structure, the light trapping effect and spectral response of the circular cross-section structure are better.

scholarly journals DEVELOPMENT MODELING OF THE REGIONAL ECONOMY IN THE INDUSTRY 4.0 CONDITIONS

2019 ◽  
Vol 8 (3) ◽  
pp. 98-108
Author(s):  
Dmitriy Vladimirovich Sirotin
Keyword(s):  
Economic Development ◽  
Economic System ◽  
Industry 4.0 ◽  
High Tech ◽  
Simulated Environment ◽  
Gravitational Model ◽  
Federal Districts ◽  
Technological Stage ◽  
The Difference ◽  
Optimal Approach

The development of the Russian economy should take into account the implementation of the Industry 4.0 concept. This concept does not have clear assessment parameters. Estimating such parameters is problematic. The development of high-tech industries is one of the main objectives of the implementation of Industry 4.0. Prediction of economic development in modern conditions is possible on the basis of mathematical modeling methods. The difference in technological stage of the domestic economy determines the feasibility of a regional approach. Agent-based modeling is the optimal approach to solving this problem. This approach allows simulating the activities of agents. The simulated environment sets the conditions for the agents to function. A gravitational model proposed to assess the economic system functioning environment. The proposed gravitational model allows us to assess the relationship between regions on the basis of high-tech trade. The approbation carried in the Sverdlovsk region conditions. As a result of the study established, the development of the Sverdlovsk region high-tech environment, covering the main industrial regions of The Urals, Volga and Siberian federal districts, and the Central Region. Purpose: Construction of the spatial development an assessing model of high-tech environment in the agent-oriented model of territories economic development in the Industry 4.0 conditions. Methodology: methods of system, structural and logical analysis, tools of gravitational modeling. Results: The proposed gravitational model allowed us to assess the interregional interrelations of Sverdlovsk region on the basis of high-tech trade. Practical implications: The results can be useful for assessing the environment of the economic system in the context of Industry 4.0 in the agent-oriented approach.

STRENGTHENING SUPPORTING COLUMNS WITH CARBON CONCRETE

2021 ◽  
Vol 95 (3) ◽  
pp. 59-67
Author(s):  
K. HOLSCHEMACHER ◽  
◽  
A.G. BULGAKOV ◽  
W. POLIENKO ◽  
◽  
...  
Keyword(s):  
Composite Material ◽  
Building Materials ◽  
Point Load ◽  
Geometrical Parameters ◽  
Building Structures ◽  
Technical School ◽  
Load Bearing ◽  
Floor Slabs ◽  
Wide Range ◽  
The Subject

Textile concrete is an innovative composite material that has been the subject of intensive research since the beginning of the 90s of the last century. After the approval of the rules and regulations on its application to strengthen floor slabs, an important step was taken towards its entry into the building materials market. Questions regarding the reinforcement of rod-shaped load-bearing elements of building structures need additional research. Despite the great potential available, the method of tying load-bearing supports and columns is still not well understood. There is a need for research on a wide range of geometric parameters and the reinforcement systems used. The Institute of Reinforced Concrete of the Higher Technical School in Leipzig tested various samples of carbon-reinforced samples in a wide range of geometrical parameters. Their goal was to assess the effect on a possible increase in the bearing capacity of carbon-reinforced columns at a concentrated point load.

Study of the Process of Self-Ignition of Coniferous Wood Samples

2019 ◽  
Vol 802 ◽  
pp. 91-99
Author(s):  
Olga Vyacheslavovna Chumakova
Keyword(s):  
Building Materials ◽  
Spontaneous Combustion ◽  
Thermal Action ◽  
The Difference ◽  
Coniferous Wood

The purpose of this work is to study the processes of spontaneous combustion of coniferous wood samples using a standard installation for determining the flammability classes of building materials "VSM", the study of the difference in the behavior of wood samples of different species under thermal action.

scholarly journals Optimal design of helical reducers for cement equipment

2019 ◽  
Vol 287 ◽  
pp. 01016
Author(s):  
Evgeniy Gudov ◽  
Sergey Lagutin
Keyword(s):  
Optimal Design ◽  
Load Capacity ◽  
Geometrical Parameters ◽  
Ball Mills ◽  
Gear Drive ◽  
Heavy Equipment ◽  
Helical Angle ◽  
The Difference ◽  
Rotary Kilns ◽  
New Generation

The trends in raising the technical level of multistage helical reducers for drives of cement, metallurgical and other heavy equipment are considered. An interactive method for optimizing the geometrical parameters of reducers with various gear ratios is proposed, which ensures equal strength of the stages in contact and bending endurance. It is shown that an increase in the hardness of the teeth requires an increase of the module and helical angle of the teeth, limitation of gear ratios, and to reduce the difference in center distances of adjacent stages. When creating a new generation of reducers, the transition to gears with carburized teeth leads to an increase in load capacity of 2.5-3 times. The examples of gear drive design for rotary kilns and ball mills are considered.

scholarly journals Estimating the Uplift Bearing Capacity of Belled Piers Adjacent to Sloping Ground by Numerical Modeling Based on Field Tests

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yangchun Han ◽  
Jiulong Cheng ◽  
Weifeng Zheng ◽  
Shijun Ding
Keyword(s):  
Numerical Modeling ◽  
Bearing Capacity ◽  
Attenuation Coefficient ◽  
Slope Angle ◽  
Field Tests ◽  
Embedment Depth ◽  
Sloping Ground ◽  
Foundation Model ◽  
The Difference ◽  
The Impact

In order to evaluate the uplift bearing capacity of belled piers beside slopes, a series of numerical simulations are carried out based on field tests data. First, a number of uplift loading tests of full-scale belled piers are carried out on the project site of transmission line in Anhui Province, China. Second, a slope-foundation model for numerical modeling is proposed and calibrated based on field tests data. The behavior of belled piers adjacent to slopes subject to uplift load is studied by numerical modeling. The impact of three parameters, including distance (a) from the belled pier to the crest of the slope, slope angle (β), and embedment depth (h) of the belled pier, has been investigated on the uplift capacity of the belled pier. Based on the simulation results, an attenuation coefficient (ω) is put forward for evaluating the reduction of uplift bearing capacity of the belled pier. The results show that the coefficient ω is negatively correlated with distance a and depth h, and the influence of distance a is greater than that of depth h according to the results of variance analysis, but the difference is not significant by F test. Moreover, the empirical equation between attenuation coefficient ω and three key factors a, β, and h had been presented by a series of fitting.

Granule Morphology of Supplementary Cementitious Materials under Different Cooling Conditions

2016 ◽  
Vol 723 ◽  
pp. 694-699
Author(s):  
Zai Bo Li ◽  
Xu Guang Zhao ◽  
San Yin Zhao ◽  
Tu Sheng He
Keyword(s):  
Building Materials ◽  
Major Axis ◽  
Cementitious Materials ◽  
Basic Oxygen Furnace ◽  
Supplementary Cementitious Materials ◽  
Basic Oxygen ◽  
Means Of Measurement ◽  
Granule Morphology ◽  
The Difference ◽  
Basic Oxygen Furnace Slag

Basic oxygen furnace slag (BOFS) , a mass supplementary cementitious materials, can be used as an active additive in building materials. The work present the result of granule morphology of two kinds of BOFS powder, cooled by water quenching (BOFS-W) and air splashing method(BOFS-A). Micrographs of two kinds of BOFS powder were observed with a scan electron microscope (SEM), then, length of major axis and minor axis of two-dimension projective outline of every granule in these SEM micrographs was measured manually and their ratio (RLB) was used to represent the granule sphericity. Each BOFS powder was divided into 6 parts with different granularity range. By means of measurement and statistical analysis, the average RLB value of granules with different granularity grade was obtained and the relation between size and sphericity of granule was explored. Result showed that BOFS-W is superior to BOFS-A in sphericity of granule. According to different granularity grade, statistical average values of RLB of BOFS-W and BOFS-A range 1.422-1.496 and 1.490-1.647, respectively. The difference of BOFS-W and BOFS-A on granule sphericity mainly is reflected in coarse granule.

scholarly journals On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Fatemeh Alavi ◽  
Amir Hossein Behravesh ◽  
Abbas S. Milani ◽  
Davoud Karimi
Keyword(s):  
Finite Element ◽  
Modulus Of Elasticity ◽  
Strain Curve ◽  
Unit Cell ◽  
Elastic Response ◽  
Geometrical Parameters ◽  
Uniaxial Test ◽  
Cell Parameters ◽  
Plastic Composite ◽  
The Difference

This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC). The ultimate goal was obtaining the optimal values of representative volume element (RVE) parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

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