הגדה של פסח

הגדה של פסח PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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הגדה של פסח

הגדה של פסח PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Electromagnetic Gauge Measurements of Shock Initiating PBX9501 and PBX9502 Explosives

Electromagnetic Gauge Measurements of Shock Initiating PBX9501 and PBX9502 Explosives PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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The authors have used an embedded electromagnetic particle velocity gauge technique to measure the shock initiation behavior in PBX9501 and PBX9502 explosives. Experiments have been conducted in which up to twelve separate measurements have been made in a single experiment which detail the growth from an input shock to a detonation. In addition, another gauge element called a shock tracker has been used to monitor the progress of the shock front as a function of time, thus providing a position-time trajectory of the wave front as it moves through the explosive sample. This provides similar data to that obtained in a traditional wedge test and is used to determine the position and time that the wave attains detonation. Data on both explosives show evidence of heterogeneous initiation (growth in the front) and homogeneous initiation (growth behind the front) with the PBX9502 showing more Heterogeneous behavior and the PBX 9501 showing more homogeneous behavior.

Manganin Gauge and Reactive Flow Modeling Study of the Shock Initiation of PBX 9501

Manganin Gauge and Reactive Flow Modeling Study of the Shock Initiation of PBX 9501 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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A series of 101mm diameter gas gun experiments was fired using manganin pressure gauges embedded in the HMX-based explosive PBX 9501 at initial temperatures of 20 C and 50 C. Flyer plate impact velocities were chosen to produce impact pressure levels in PBX 9501 at which the growth of explosive reaction preceding detonation was measured on most of the gauges and detonation pressure profiles were recorded on some of the gauges placed deepest into the explosive targets. All measured pressure histories for initial temperatures of 25 C and 50 C were essentially identical. Measured run distances to detonation at several input shock pressures agreed with previous results. An existing ignition and growth reactive flow computer model for shock initiation and detonation of PBX 9501, which was developed based on LANL embedded particle velocity gauge data, was tested on these pressure gauge results. The agreement was excellent, indicating that the embedded pressure and particle velocity gauge techniques yielded consistent results.

Initiation of Preshocked High Explosives PBX-9404, PBX-9502, PBX-9501, Monitored with In-material Magnetic Gauging

Initiation of Preshocked High Explosives PBX-9404, PBX-9502, PBX-9501, Monitored with In-material Magnetic Gauging PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

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Book Description
Desensitization of explosives by preshocking is being studied using the well-supported plane shock waves generated by a gas gun. Evolution of the waves in the explosive is monitored using in-material multiple magnetic gauges to measure particle velocity in the lagrangian frame, over ≈ 3[mu]s of run. PBX-9404, PBX-9502 have been studied, at pressures up to 10.5 GPa. A substantial extension of the run to detonation is observed in PBX-9404, with the run beginning approximately at the end of the preshocked region. A reactive wave is observed while the preshock persists in both PBX-9404 and PBX-9501, but evidently does not contribute to the detonation wave or shorten the run to detonation. PBX-9502 is inert at pressures accessible with the gas gun, but serves to clarify the progress of multiple shocks over the off-Hugoniot EOS surface and the shock dynamics of wave coalescence.

Shock Wave Science and Technology Reference Library, Vol. 3

Shock Wave Science and Technology Reference Library, Vol. 3 PDF Author: Yasuyuki Horie
Publisher: Springer Science & Business Media
ISBN: 3540770801
Category : Science
Languages : en
Pages : 294

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Book Description
This book is the second volume of Solids Volumes in theShockWaveScience and Technology Reference Library. These volumes are primarily concerned with high-pressure shock waves in solid media, including detonation and hi- velocity impact and penetration events. This volume contains four articles. The ?rst two describe the reactive behavior of condensed-phase explosives, and the remaining two discuss the inert, mechanical response of solid materials. The articles are each se- contained, and can be read independently of each other. They o?er a timely reference, for beginners as well as professional scientists and engineers, cov- ing the foundations and the latest progress, and include burgeoning devel- ment as well as challenging unsolved problems. The ?rst chapter, by S. She?eld and R. Engelke, discusses the shock initiation and detonation phenomena of solids explosives. The article is an outgrowth of two previous review articles: “Explosives” in vol. 6 of En- clopedia of Applied Physics (VCH, 1993) and “Initiation and Propagation of Detonation in Condensed-Phase High Explosives” in High-Pressure Shock Compression of Solids III (Springer, 1998). This article is not only an - dated review, but also o?ers a concise heuristic introduction to shock waves and condensed-phase detonation. The authors emphasize the point that d- onation is not an uncontrollable, chaotic event, but that it is an orderly event that is governed by and is describable in terms of the conservation of mass, momentum, energy and certain material-speci?c properties of the explosive.

SHOCK INITIATION EXPERIMENTS ON PBX 9501 EXPLOSIVE AT PRESSURES BELOW 3 GPa WITH ASSOCIATED IGNITION AND GROWTH MODELING.

SHOCK INITIATION EXPERIMENTS ON PBX 9501 EXPLOSIVE AT PRESSURES BELOW 3 GPa WITH ASSOCIATED IGNITION AND GROWTH MODELING. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
Shock initiation experiments on the explosive PBX 9501 (95% HMX, 2.5% estane, and 2.5% nitroplasticizer by weight) were performed at pressures below 3 GPa to obtain in-situ pressure gauge data, run-distance-to-detonation thresholds, and Ignition and Growth modeling parameters. Propellant driven gas guns (101 mm and 155 mm) were utilized to initiate the PBX 9501 explosive with manganin piezoresistive pressure gauge packages placed between sample slices. The run-distance-to-detonation points on the Pop-plot for these experiments showed agreement with previously published data and Ignition and Growth modeling parameters were obtained with a good fit to the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios in the low-pressure regime (below 3 GPa) involving PBX 9501 explosive.

Energetic Materials

Energetic Materials PDF Author: Ulrich Teipel
Publisher: John Wiley & Sons
ISBN: 3527604936
Category : Science
Languages : en
Pages : 643

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Book Description
Incorporation of particular components with specialized properties allows one to tailor the end product's properties. For instance, the sensitivity, burning behavior, thermal or mechanical properties or stability of energetic materials can be affected and even controllably varied through incorporation of such ingredients. This book examines particle technologies as applied to energetic materials such as propellants and explosives, thus filling a void in the literature on this subject. Following an introduction covering general features of energetic materials, the first section of this book describes methods of manufacturing particulate energetic materials, including size reduction, crystallization, atomization, particle formation using supercritical fluids and microencapsulation, agglomeration phenomena, special considerations in mixing explosive particles and the production of nanoparticles. The second section discusses the characterization of particulate materials. Techniques and methods such as particle size analysis, morphology elucidation and the determination of chemical and thermal properties are presented. The wettability of powders and rheological behavior of suspensions and solids are also considered. Furthermore, methods of determining the performance of particular energetic materials are described. Each chapter deals with fundamentals and application possibilities of the various methods presented, with particular emphasis on issues applicable to particulate energetic materials. The book is thus equally relevant for chemists, physicists, material scientists, chemical and mechanical engineers and anyone interested or engaged in particle processing and characterization technologies.

Shock Compression of Condensed Matter - 2005

Shock Compression of Condensed Matter - 2005 PDF Author: Michael D. Furnish
Publisher: American Institute of Physics
ISBN: 9780735403413
Category : Science
Languages : en
Pages : 842

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Book Description
This book constitutes the Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, Baltimore, Maryland USA, 2005. The volume embodies the most recent research on shock compression of condensed matter and includes 363 plenary, invited, and contributed papers, all peer-reviewed. Topics include: equations of state, phase transitions, chemical reactions, warm dense matter, fracture, geophysics and planetary science, energetic materials, optical studies, and more.

Modeling The Shock Initiation of PBX-9501 in ALE3D.

Modeling The Shock Initiation of PBX-9501 in ALE3D. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Book Description
The SMIS (Specific Munitions Impact Scenario) experimental series performed at Los Alamos National Laboratory has determined the 3-dimensional shock initiation behavior of the HMX-based heterogeneous high explosive, PBX 9501. A series of finite element impact calculations have been performed in the ALE3D [1] hydrodynamic code and compared to the SMIS results to validate the code predictions. The SMIS tests use a powder gun to shoot scaled NATO standard fragments at a cylinder of PBX 9501, which has a PMMA case and a steel impact cover. The SMIS real-world shot scenario creates a unique test-bed because many of the fragments arrive at the impact plate off-center and at an angle of impact. The goal of this model validation experiments is to demonstrate the predictive capability of the Tarver-Lee Ignition and Growth (I & G) reactive flow model [2] in this fully 3-dimensional regime of Shock to Detonation Transition (SDT). The 3-dimensional Arbitrary Lagrange Eulerian hydrodynamic model in ALE3D applies the Ignition and Growth (I & G) reactive flow model with PBX 9501 parameters derived from historical 1-dimensional experimental data. The model includes the off-center and angle of impact variations seen in the experiments. Qualitatively, the ALE3D I & G calculations accurately reproduce the 'Go/No-Go' threshold of the Shock to Detonation Transition (SDT) reaction in the explosive, as well as the case expansion recorded by a high-speed optical camera. Quantitatively, the calculations show good agreement with the shock time of arrival at internal and external diagnostic pins. This exercise demonstrates the utility of the Ignition and Growth model applied in a predictive fashion for the response of heterogeneous high explosives in the SDT regime.

Numerical Calculation of Shock-induced Initiation of Detonations. [PBX 9501].

Numerical Calculation of Shock-induced Initiation of Detonations. [PBX 9501]. PDF Author:
Publisher:
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Category :
Languages : en
Pages :

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Book Description
The results of some numerical calculations of the impact of steel cylinders and spheres on the plastic-bonded high explosive PBX 9501 are described. The calculations were carried out by a reactive, multicomponent, two-dimensional, Eulerian hydrodynamic computer code, 2DE. The 2DE computer code is a finite difference code that uses the donor-acceptor-cell method to compute mixed cell fluxes. The mechanism of shock initiation to detonation in heterogeneous explosives is best described as local decomposition at hot spots that are formed by shock interactions with density discontinuities. The liberated energy strengthens the shock so that as it interacts with additional inhomogeneities, hotter hot spots are formed, and more of the explosive is decomposed. The shock wave grows stronger until a detonation begins. This mechanism of initiation has been described numerically by the Forest Fire burn model, which gives the rate of explosive decomposition as a function of local pressure. The parameters in the Forest Fire burn model have been developed from experiments where the induced shock approximates a plane wave and are applied, in this case, to a situation where the induced shock is a divergent wave with curvature that depends on the size and shape of the projectile. The calculated results have been compared with results from experiments involving instrumented mock and live high explosives, with projectiles of varying sizes, shapes, and velocities. We find that there is good agreement between the calculated and experimental data.