Effective use of overdriven detonation in high explosives

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.

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Investigation of Jet Formation with Overdriven Detonation in High Density Explosive

Materials Science Forum ◽

10.4028/www.scientific.net/msf.566.327 ◽

2007 ◽

Vol 566 ◽

pp. 327-332 ◽

Cited By ~ 2

Author(s):

Hisaatsu Kato ◽

Kenji Murata ◽

Shigeru Itoh ◽

Yukio Kato

Keyword(s):

Numerical Simulation ◽

Detonation Velocity ◽

Tungsten Powder ◽

High Density ◽

Shaped Charge ◽

Detonation Pressure ◽

Jet Formation ◽

High Explosives ◽

Overdriven Detonation ◽

Penetration Velocity

To increase largely the performance of shaped charge, it is required to generate detonation velocity much higher than CJ velocity or detonation pressure much higher than CJ pressure of existing high explosives. One solution is the application of overdriven detonation phenomena. In this study, the effects of overdriven detonation in tungsten loaded high density explosive on the performance of shaped charge were demonstrated by experiments and numerical simulation. Sample shaped charge was composed of the inner layer tungsten loaded high density PBX and outer layer high velocity PBX. Concentration of tungsten powder in high density PBX was varied from 20 to 60% in mass. The pressure of overdriven detonation in inner layer PBX was measured by PMMA gauge, and was shown to be higher than 50GPa. The experimental results showed that the initial jet velocity and jet penetration velocity in target plates were largely increased by the effects of the overdriven detonation in tungsten loaded high density PBX.

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Analysis of 3-d molecular distribution with the digital imaging microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102286 ◽

1988 ◽

Vol 46 ◽

pp. 40-41

Author(s):

W.A. Carrington ◽

F.S. Fay ◽

K.E. Fogarty ◽

L. Lifshitz

Keyword(s):

Image Restoration ◽

Digital Imaging ◽

Fluorescent Dyes ◽

Optical Axis ◽

Computer Hardware ◽

Computer Algorithms ◽

Low Contrast ◽

Specific Proteins ◽

Effective Use ◽

Single Living Cells

Advances in digital imaging microscopy and in the synthesis of fluorescent dyes allow the determination of 3D distribution of specific proteins, ions, GNA or DNA in single living cells. Effective use of this technology requires a combination of optical and computer hardware and software for image restoration, feature extraction and computer graphics.The digital imaging microscope consists of a conventional epifluorescence microscope with computer controlled focus, excitation and emission wavelength and duration of excitation. Images are recorded with a cooled (-80°C) CCD. 3D images are obtained as a series of optical sections at .25 - .5 μm intervals.A conventional microscope has substantial blurring along its optical axis. Out of focus contributions to a single optical section cause low contrast and flare; details are poorly resolved along the optical axis. We have developed new computer algorithms for reversing these distortions. These image restoration techniques and scanning confocal microscopes yield significantly better images; the results from the two are comparable.

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Effective use of health care information

Health Libraries Review ◽

10.1046/j.1365-2532.1997.1440201.x ◽

1997 ◽

Vol 14 (4) ◽

pp. 201-208

Author(s):

PETER MERRY

Keyword(s):

Health Care ◽

Health Care Information ◽

Care Information ◽

Effective Use ◽

Use Of Health Care

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Effective use of capital budgeting tools

Business Horizons ◽

10.1016/s0007-6813(75)80008-5 ◽

1975 ◽

Vol 19 (5) ◽

pp. 57-65 ◽

Cited By ~ 7

Author(s):

G PETRY

Keyword(s):

Capital Budgeting ◽

Effective Use

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The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000084 ◽

2012 ◽

Vol 220 (1) ◽

pp. 3-9 ◽

Cited By ~ 4

Author(s):

Sandra Sülzenbrück

Keyword(s):

Empirical Research ◽

Visual Feedback ◽

Closed Loop ◽

Motor Planning ◽

Visual Input ◽

Closed Loop Control ◽

Loop Control ◽

Feedback Type ◽

Effective Use ◽

The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

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