scholarly journals Control of density and velocity of emulsion explosives detonation for ore breaking

2021 ◽  
pp. 69-75
Author(s):  
M.M Kononenko ◽  
O.Ye Khomenko ◽  
I.L Kovalenko ◽  
M.V Savchenko
Keyword(s):  
Hydrostatic Pressure ◽  
Detonation Velocity ◽  
Initial Density ◽  
Experimental Tests ◽  
Column Length ◽  
Emulsion Explosives ◽  
Detonation Rate ◽  
Calculation Results ◽  
The Face ◽  
Inclination Angles

Purpose.Development of a new procedure for calculating the density of emulsion explosives (EE), that will allow determining the detonation velocity along the charging length, depending on the inclination of boreholes during ore breaking. Methodology.A calculation method for the redistribution of EE density and mass in boreholes at different angles of inclination has been developed by using the well-known laws of hydrostatics. Measurement of the detonation velocity of the EE Ukrainit-PP-2B was conducted by using the method of polygon experimental tests. The numerical simulation of changes in the detonation velocity of explosives in boreholes was conducted by using the proposed method and established regularities. Findings.Methods of calculation of EE density changing along the charging column length under the action of hydrostatic pressure at different angles of inclination of both ascending and descending boreholes have been developed. Based on experimental data, regularities of detonation rate changing from density and charge diameter for EE Ukrainit-PP-2B, varying according to exponential law have been established. The rational initial density of EE Ukrainit-PP-2B has been established for ores breaking by boreholes, which is equal to 8001000 kg/m3, at which the detonation rate along the length of the charge column at different angles of inclination of the boreholes is maintained. The obtained results will allow controlling density and detonation velocity during ore breaking. Originality.The density of EE increases in the formed charging column under the action of hydrostatic pressure: in ascending boreholes from the face, while in descending boreholes from the brow. Practical value.Application of the calculation results of EE density at different inclination angles of boreholes makes it possible to determine in the charge column sections with its critical values more than 1410 kg/m3, at which a sharp attenuation of the detonation rate begins. Consideration of this phenomenon makes it possible to prevent the occurrence of failures at the explosion of charges in boreholes during ore breaking.

scholarly journals Interlocking birch plywood structures

2021 ◽  
pp. 095605992110222
Author(s):  
Chrysl A Aranha ◽  
Markus Hudert ◽  
Gerhard Fink
Keyword(s):  
High Surface ◽  
Surface Hardness ◽  
Experimental Tests ◽  
Digital Fabrication ◽  
Element Model ◽  
Component Level ◽  
Geometrical Properties ◽  
Stiffness Properties ◽  
The Face ◽  
Strength And Stiffness

Interlocking Particle Structures (IPS) are geometrically stable assemblies, usually fabricated from plate type elements that are interconnected by slotted joints. IPS are demountable and their components have the potential to be used and reused in different structures and configurations. This paper explores the applicability of birch plywood panels, which are characterized by a high surface hardness, for this type of structural system. Experimental tests were conducted to determine the mechanical properties of birch plywood plates. Moreover, IPS connections with different geometrical properties were investigated for two different load exposures: bending and rotation. The characteristics under bending exposure are influenced by the orientation of the face-veneers. For the rotational load exposure, very small strength and stiffness properties have been identified. A linear elastic finite element model is presented that shows a wide agreement with the test results. The study serves as an initial probe into the performance of IPS structures at the component level. Various aspects that are relevant for the design of IPS, such as the assembly, the accuracy and challenges regarding digital fabrication, the durability, and the structural performance are discussed.

scholarly journals NUMERICAL ANALYSIS OF CORRUGATED STEEL PLATE BRIDGE WITH REINFORCED CONCRETE RELIEVING SLAB

2015 ◽  
Vol 22 (5) ◽  
pp. 585-596 ◽  
Author(s):  
Damian BEBEN ◽  
Adam STRYCZEK
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Steel Plate ◽  
Numerical Models ◽  
Experimental Tests ◽  
Bridge Engineering ◽  
Steel Plates ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Rc Slab

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements.

Novel Technique for 3D Face Recognition Using Anthropometric Methodology

2018 ◽  
Vol 9 (1) ◽  
pp. 60-77 ◽  
Author(s):  
Souhir Sghaier ◽  
Wajdi Farhat ◽  
Chokri Souani
Keyword(s):  
Face Recognition ◽  
Learning Algorithm ◽  
Recognition Performance ◽  
Experimental Tests ◽  
3D Face Recognition ◽  
3D Face ◽  
Area Of Interest ◽  
The Face ◽  
Face Datasets ◽  
Improved Technique

This manuscript presents an improved system research that can detect and recognize the person in 3D space automatically and without the interaction of the people's faces. This system is based not only on a quantum computation and measurements to extract the vector features in the phase of characterization but also on learning algorithm (using SVM) to classify and recognize the person. This research presents an improved technique for automatic 3D face recognition using anthropometric proportions and measurement to detect and extract the area of interest which is unaffected by facial expression. This approach is able to treat incomplete and noisy images and reject the non-facial areas automatically. Moreover, it can deal with the presence of holes in the meshed and textured 3D image. It is also stable against small translation and rotation of the face. All the experimental tests have been done with two 3D face datasets FRAV 3D and GAVAB. Therefore, the test's results of the proposed approach are promising because they showed that it is competitive comparable to similar approaches in terms of accuracy, robustness, and flexibility. It achieves a high recognition performance rate of 95.35% for faces with neutral and non-neutral expressions for the identification and 98.36% for the authentification with GAVAB and 100% with some gallery of FRAV 3D datasets.

scholarly journals Estimation of Influence of Explosive Characteristics of Emulsion Explosives on Shotpile Width

2018 ◽  
Vol 56 ◽  
pp. 01003
Author(s):  
Victor Sinitsyn ◽  
Pavel Menshikov ◽  
Vyacheslav Kutuev
Keyword(s):  
Detonation Velocity ◽  
Dynamic Compression ◽  
Point Of View ◽  
Head Part ◽  
Detonation Pressure ◽  
Emulsion Explosives ◽  
Clastic Rocks ◽  
Total Magnitude ◽  
Efficient Type ◽  
Points Of View

The article deals with the question of the effect of explosive characteristics of emulsion explosives on the shotpile width. Currently, there are two main points of view to select an efficient type of explosive, which contributes to the qualitative destruction (fragmentation) of coarse clastic rocks. The first is based on the assumption that the detonation velocity of explosives must correspond to the break-down point of the rock (dynamic compression). Another point of view is that the detonation pressure of explosives determines only the head part of the pulse, on which the rock fragmentation is dependent only near the charge, in the contact zone around the borehole. The fragmentation of the entire rock volume within a given borehole array depends on the total magnitude of the explosion pulse, determined not by the detonation velocity, but by the total energy reserve of the explosive charge. Experimental explosions with some of the most common industrial explosives have been carried out in the current conditions of blasting of borehole charges by various types of industrial explosives from the point of view to select the most important parameter, which determines its influence on the shotpile width The investigations have been carried out according to the data obtained to establish that the energy properties of explosives (heat of explosive transformation and density of explosives) determine the decisive influence on the shotpile width, and the operability, the volume of the released gases, the detonation velocity for the change in the shotpile width have very little effect and may not be taken into account in calculations for the prediction of the shotpile.

Investigation of low detonation velocity emulsion explosives

2009 ◽  
Vol 45 (5) ◽  
pp. 618-626 ◽  
Author(s):  
V. V. Sil’vestrov ◽  
A. V. Plastinin
Keyword(s):  
Detonation Velocity ◽  
Emulsion Explosives

Using noise control principles when evaluating the acoustic impacts of face coverings during the coronavirus pandemic

2021 ◽  
Vol 263 (3) ◽  
pp. 3554-3561
Author(s):  
Richard Ruhala ◽  
Laura Ruhala
Keyword(s):  
Classroom Environment ◽  
Noise Control ◽  
Experimental Tests ◽  
Analytical Models ◽  
Octave Band ◽  
Interference Level ◽  
Cavity Resonances ◽  
The Face ◽  
Clear Plastic ◽  
Stiffness And Damping

Several different combinations of face masks and shields are evaluated for their acoustic performance using a head and torso simulator (HATS). The HATS is used as a controlled and repeatable artificial sound source using white noise in a classroom environment. Sound pressure levels at octave band frequencies due to the face coverings are evaluated at a location of 2.0 meters from the HATS which is within the direct field to reduce the room acoustical effects. The problem is modeled as a barrier separating a source and receiver using fundamental noise control principles. Fabric material properties are used such as thickness, density, stiffness, and damping. The results are compared with experimental tests. The face shield with clear plastic barrier produces a resonance in the 1000 Hz octave band. Analytical models of cavity resonances, standing wave resonances, or plate resonances are calculated and compared with the experimental resonance. The speech interference level is used to determine the frequency content that is most likely to cause hearing difficulties and compared with A-weighted differences between the unmasked condition and masked.

The influence of temperature on the detonation velocity of selected emulsion explosives

2019 ◽  
Vol 38 (3) ◽  
pp. 336-347
Author(s):  
Piotr Mertuszka ◽  
Krzysztof Fuławka ◽  
Mateusz Pytlik ◽  
Michał Szastok
Keyword(s):  
Detonation Velocity ◽  
Emulsion Explosives ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

scholarly journals Study on the Coupling Frequency of Double-Sided Submerged Ring-Stiffened Cylindrical Shells

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Anbin Yu ◽  
Yinglong Zhao ◽  
Youqian Wang ◽  
Ben Zhang
Keyword(s):  
Cylindrical Shell ◽  
Free Surface ◽  
Hydrostatic Pressure ◽  
Water Immersion ◽  
Theoretical Method ◽  
Coupling Model ◽  
Acoustic Vibration ◽  
Stiffened Cylindrical Shell ◽  
Calculation Results ◽  
Coupling Frequency

Based on the Flügge theory and orthotropic theory, the acoustic vibration coupling model of ring-stiffened cylindrical shell is established by using the wave propagation method and virtual source method. And the effects of water immersion on both sides, free surface, and hydrostatic pressure on the cylindrical shell are considered in the coupling model. Muller three-point iterative method is used to solve the coupling frequency. The calculation results of degradation theory are compared with COMSOL’s calculation results and experimental results, respectively, which verifies the reliability of the theoretical method. Finally, the influence of fluid load, ring rib parameters, boundary conditions, hydrostatic pressure, and free surface on the coupled vibration of ring-stiffened cylindrical shell is analyzed by an example.

Systematic study of Ethylene-Vinyl Acetate (EVA) in the manufacturing of protector devices for the orofacial system

2017 ◽  
Vol 1 (86) ◽  
pp. 24-31
Author(s):  
R.B. Dias ◽  
N.P. Coto ◽  
G.F. Batalha ◽  
L. Driemeier
Keyword(s):  
Systematic Study ◽  
Thick Plate ◽  
Complex Geometry ◽  
Experimental Tests ◽  
Ethylene Vinyl Acetate ◽  
Systematic Evaluation ◽  
Zygomatic Bone ◽  
The Face ◽  
Bone Protection ◽  
Practical Implications

Purpose: This study aims to provide a systematic evaluation of the EVA application in orofacial protectors while focusing on sports. Design/methodology/approach: The research comprises a numerical analysis. During experimental tests, EVA was analysed in special more specific studies about its influence on the mechanical behaviour of EVA were performed. In the numerical analyses of the EVA orofacial protector, the studies focused on its effect in the zygomatic bone protection, in a simplified geometry. Findings: According to the experimental and numerical results from a systematic study of EVA, its application to orofacial protection can be considered satisfactory. Research limitations/implications: The limitations for this research is the complex geometry of the face, number of materials and parameters involved in this study. Practical implications: For facial protection, a better performance is obtained with a combination of rigid and soft EVA material. Particularly for the zygomatic bone, a 3 mm thick plate of soft EVA overlapped by a 1 mm thick plate of rigid EVA is indicated. Originality/value: The studies made for this researchers group show that the EVA use in facial protection for sports is effective.

CASTEP Calculation of Surface Energy of α-Al2O3

2012 ◽  
Vol 512-515 ◽  
pp. 490-493 ◽  
Author(s):  
Yan Yuan Liang ◽  
Da Ming Chen ◽  
Jiang Feng Tong
Keyword(s):  
First Principles ◽  
Growth Habit ◽  
First Principles Calculations ◽  
Crystal Face ◽  
Exchange Correlation ◽  
Calculation Results ◽  
The Face ◽  
Α Al2o3 ◽  
Materials Studio ◽  
Good Agreement

First principles calculations were run on bulk and the （110）（001）（012）（113） surfaces of α-Al2O3 in order to examine the growth habit of α-Al2O3 crystals.The Materials Studio package was used, specifically the program CASTEP, utilizing Perdew Burke Ernzerh of exchange-correlation pseudo-potentials. The calculation results shows that the ranking of the face energy on different crystal face are E(001)‹ E(113) ‹ E(012) ‹E(110) which is in good agreement with experiment phenomenon observed that the ranking of the growth rates of different crystal faces are V(001) ‹ V(113) ‹ V(012) ‹ V(110).

Sign in / Sign up

Export Citation Format

Share Document