scholarly journals Imaging of Bubble Collapse Effects in Optically Transparent High Explosive as a Method to Study the Detonation Process STL-017-19, Year 2

2020 ◽  
Author(s):  
William Turley
Keyword(s):  
High Explosive ◽  
Bubble Collapse ◽  
Optically Transparent ◽  
Detonation Process

The Performance of Pressure Vessel Using Concentric Double Cylindrical High Explosive

2004 ◽  
Vol 126 (4) ◽  
pp. 409-413 ◽  
Author(s):  
Toru Hamada ◽  
Yuichi Nakamura ◽  
Shigeru Itoh
Keyword(s):  
High Velocity ◽  
High Explosive ◽  
Maximum Pressure ◽  
Detonation Pressure ◽  
Low Velocity ◽  
High Explosives ◽  
Detonation Process ◽  
Set Up ◽  
Overdriven Detonation ◽  
Detonation Phenomenon

The detonation pressure from the steady detonation of high explosives is a characteristic. Nevertheless, in materials processing using high explosives, there are cases when the detonation pressure does not match the intended pressure. In this investigation, as a new method of generating the overdriven detonation effectively, a double cylindrical high explosive set up using two kinds of explosives was developed, and its basic performance is analyzed. The concentric double cylindrical high explosive set up was composed of a high velocity explosive and a low velocity explosive, and the overdriven detonation was performed in the low velocity explosive. In this experiment, the ion gap was set up in the high velocity explosive and low velocity explosive respectively, and the detonation velocity was measured. The detonation pressure was also measured by setting up a manganin gauge (Kyowa Electric Instrument Co., Ltd.,) at the position where the generation of the overdriven detonation phenomenon was expected. Furthermore, the overdriven detonation process of the concentric double cylindrical high explosive was continually observed by numerical analysis and the framing photography. From the experimental results, the very high pressure region including the mach stem was observed in the low velocity explosive, and the overdriven detonation phenomenon was confirmed. The maximum pressure value of the concentric double cylindrical high explosive set up was 2.3 times higher than the Chapman-Jouguet pressure of the single explosive.

Analysis of Shell Material Influence on Detonation Process in High Explosive Charge

2016 ◽  
Vol 715 ◽  
pp. 27-32 ◽  
Author(s):  
Igor Balagansky ◽  
Alexey Vinogradov ◽  
Lev Merzhievsky ◽  
Alexander Matrosov ◽  
Ivan Stadnichenko
Keyword(s):  
Explosive Charge ◽  
Symmetry Axis ◽  
High Explosive ◽  
Detonation Front ◽  
Detonation Pressure ◽  
Ceramic Shell ◽  
Shell Material ◽  
Detonation Products ◽  
Transverse Waves ◽  
Detonation Process

The influence of the shell material (copper and silicon carbide) on the detonation process in cylindrical high explosive charge is experimentally and numerically investigated. We observed the significant differences of wave pictures in the detonation products and in the shells, which were due to differences in the sound velocities in the shells and rapid destruction of the ceramic shell under explosion loading. The specific features of a wave picture at the interface HE/ceramics due to desensitization of explosive under loading by an advanced wave in the shell were detected. Those features lead to decreasing of detonation pressure, blurring of the detonation front, and to increasing of mass velocity behind detonation front that is typical for under-compressed detonation. On the symmetry axis of HE charge in the ceramic shell behind the detonation front the long zone with practically constant pressure was observed. We have identified the mechanism of transmission of disturbances from the periphery to the symmetry axis of the HE charge. The source of the emergence of this zone is identified as transverse waves propagating directly behind the detonation front from the periphery to the symmetry axis of the HE charge.

Dislocations, Ordering and Antiferromagnetic Domains in MnO

1970 ◽  
Vol 28 ◽  
pp. 522-523
Author(s):  
D. J. Barber ◽  
R. G. Evans
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Optical Microscopy ◽  
Defect Chemistry ◽  
Magnetic Structures ◽  
Optically Transparent ◽  
Magnetic Features ◽  
Antiferromagnetic Domains

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.

Influence of magnetic field to the allocation of imputiry molecules in the structure of optically transparent polymer films

2016 ◽  
Vol 38 (3) ◽  
pp. 205-210
Author(s):  
L.A. Bulavin ◽  
◽  
Yu.F. Zabashta ◽  
О.О. Brovko ◽  
L.Yu. Vergun ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Polymer Films ◽  
Optically Transparent
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