scholarly journals Effect of aluminium additives on selected detonation parameters of a bulk emulsion explosive

2020 ◽  
pp. 99-113
Author(s):  
Bartłomiej Kramarczyk ◽  
Mateusz Pytlik ◽  
Piotr Mertuszka
Keyword(s):  
Detonation Velocity ◽  
Free Field ◽  
Aluminium Content ◽  
Velocity Measurements ◽  
Emulsion Explosive ◽  
Emulsion Explosives ◽  
Air Blast ◽  
Explosive Strength ◽  
Detonation Parameters

The article presents an assessment of the influence of aluminium granules content on selected detonation parameters of a chemically sensitised bulk emulsion explosive. The analysis covered determination of relative explosive strength using a ballistic mortar and Trauzl blocks, free field air blast tests and detonation velocity measurements. Five types of emulsion explosives with differing aluminium content were tested at loadings of 0, 1, 3, 5 and 7%.

scholarly journals Enhancement of Explosive Welding Possibilities by the Use of Emulsion Explosive/ Rozwój Mozliwości Łączenia Wybuchowego Przez Użycie Emulsji Wybuchowych

2014 ◽  
Vol 59 (4) ◽  
pp. 1587-1592 ◽  
Author(s):  
B. Zlobin ◽  
V. Sil’Vestrov ◽  
A. Shtertser ◽  
A. Plastinin ◽  
V. Kiselev
Keyword(s):  
Thin Layer ◽  
Physical Properties ◽  
Detonation Velocity ◽  
Explosive Welding ◽  
Hardened Steel ◽  
Explosion Welding ◽  
Thin Layers ◽  
Emulsion Explosive ◽  
Emulsion Explosives ◽  
Thermo Physical Properties

Abstract Explosive welding is an effective method of joining of various metals and alloys. However, when the materials with very different strength and thermo-physical properties are welded or thin-layer cladding is performed, the difficulties occur which call for extra investigations. In the present paper, with the couples of steel / carbide composite and copper / hardened steel used as examples, under study were the peculiarities of bonding formation by the explosive welding of metals with highly differing properties. The experiments were carried out with emulsion explosive containing hollow micro-spheres and detonating in thin layers with the low (2 - 3 km/s) detonation velocity. Obtained results show that the emulsion explosives enable to extend the explosion welding potentiality.

scholarly journals Scaled-down test arrangements for characterizing high explosives

2021 ◽  
pp. 28-33
Author(s):  
Martin Künzel ◽  
Jindrich Kučera
Keyword(s):  
Experimental Determination ◽  
Detonation Velocity ◽  
Sufficient Data ◽  
High Explosives ◽  
Test Set ◽  
Detonation Parameters ◽  
Labour Costs ◽  
Velocity Pressure

Newly formulated explosives and the optimization of explosive mixtures requires an experimental determination of detonation parameters, especially detonation velocity, pressure and metal accelerating ability. Increasing material and labour costs force researchers to reduce test quantities and therefore to develop smaller scale experiments which provide sufficient data to determine an explosive’s properties. Seven test set-ups found in literature are described and compared in this paper.

scholarly journals Mass determination of the 1:3:5 near-resonant planets transiting GJ 9827 (K2-135)

2018 ◽  
Vol 618 ◽  
pp. A116 ◽  
Author(s):  
J. Prieto-Arranz ◽  
E. Palle ◽  
D. Gandolfi ◽  
O. Barragán ◽  
E. W. Guenther ◽  
...  
Keyword(s):  
Planetary System ◽  
Initial Conditions ◽  
Dynamical Evolution ◽  
Space Mission ◽  
Mass Determination ◽  
Velocity Measurements ◽  
Orbital Periods ◽  
The Masses ◽  
Better Than

Context. Multiplanet systems are excellent laboratories to test planet formation models as all planets are formed under the same initial conditions. In this context, systems transiting bright stars can play a key role, since planetary masses, radii, and bulk densities can be measured. Aims. GJ 9827 (K2-135) has recently been found to host a tightly packed system consisting of three transiting small planets whose orbital periods of 1.2, 3.6, and 6.2 days are near the 1:3:5 ratio. GJ 9827 hosts the nearest planetary system (~30 pc) detected by NASA’s Kepler or K2 space mission. Its brightness (V = 10.35 mag) makes the star an ideal target for detailed studies of the properties of its planets. Methods. Combining the K2 photometry with high-precision radial-velocity measurements gathered with the FIES, HARPS, and HARPS-N spectrographs we revised the system parameters and derive the masses of the three planets. Results. We find that GJ 9827 b has a mass of Mb = 3.69−0.46+0.48 M⊕ and a radius of Rb = 1.58−0.13+0.14 R⊕, yielding a mean density of ρb = 5.11−1.27+1.74 g cm−3. GJ 9827 c has a mass of Mc = 1.45−0.57+0.58 M⊕, radius of Rc = 1.24−0.11+0.11 R⊕, and a mean density of ρc = 4.13−1.77+2.31 g cm−3. For GJ 9827 d, we derive Md = 1.45−0.57+0.58 M⊕, Rd = 1.24−0.11+0.11 R⊕, and ρd = 1.51−0.53+0.71 g cm−3. Conclusions. GJ 9827 is one of the few known transiting planetary systems for which the masses of all planets have been determined with a precision better than 30%. This system is particularly interesting because all three planets are close to the limit between super-Earths and sub-Neptunes. The planetary bulk compositions are compatible with a scenario where all three planets formed with similar core and atmosphere compositions, and we speculate that while GJ 9827 b and GJ 9827 c lost their atmospheric envelopes, GJ 9827 d maintained its primordial atmosphere, owing to the much lower stellarirradiation. This makes GJ 9827 one of the very few systems where the dynamical evolution and the atmosphericescape can be studied in detail for all planets, helping us to understand how compact systems form and evolve.

Determination of global kinetic parameters by optimization procedure using burning velocity measurements

2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev
Keyword(s):  
Kinetic Parameters ◽  
Equivalence Ratio ◽  
Reaction Rate ◽  
Functional Dependence ◽  
Burning Velocity ◽  
Optimization Procedure ◽  
Optimal Parameters ◽  
Velocity Measurements ◽  
Equilibrium Calculations

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.

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