bluuebunny/crossref_metadata_2025_split huggingface dataset:
Setback Testing of ANFO and Water‐Based Explosives
Authors: Listh O. 
Published: December 2004

AbstractIn a setback simulator a gunpowder charge is used to drive a heavily confined sample of explosive against a stationary plunger. The pressure on the sample, the sample velocity, and the acceleration of the sample are recorded. The results found show that the degree of confinement of the sample is an important test parameter. The results for civil AN‐based explosives show that water gels containing sensitizers are easier to initiate than the military explosive Comp. B, whereas non‐cap‐sensitive slurries could not be initiated in this test. There was no obvious difference in sensitivity between water gels with or without aluminium content. Contrary to this, ANFO containing aluminium showed a higher sensitivity than did pure ANFO. Critical pressures on the sample were in the range of 0.04 GPa‐0.14 GPa, and the corresponding sample velocities ranged from 8 m/s to 27 m/s. Sample decelerations when hitting the plunger were in the range of 30 m/s2‐80 km/s2.
Methode zur Bestimmung des Zündvermögens von Sprengkapseln und Sprengzündern
Authors: Prior J. 
Published: December 2004

AbstractEs wird über eine Prüfmethode der Fa. Dynamit Nobel AG berichtet, bei der mit einer einzigen Prüfmischung die gesamte Skala der Zündstärken der technisch verwendeten Sprengkapseln und Sprengzünder erfaßt werden kann. Der Aufbau der Prüfanordnung, das Herstellen des Prüfsprengstoffs und der Prüfladung werden beschrieben, Versuchsergebnisse werden diskutiert.
Strength Testing of Explosives by Underwater Detonation
Authors: Bjarnholt G. 
Published: December 2004

AbstractShock wave energy and bubble energy for different explosives have been measured in underwater experiments. A method to determine bubble energies in cases where the free water surface and bottom boundary disturb the bubble oscillation has been developed. The shock energy loss when the primary shock wave travels from the charge to the gage resulting in heating of the surrounding water has been estimated by correlation with data derived from detonation calorimeter experiments for some explosives. Comparison of the measured total expansion work with data from thermodynamic computer calculations show good agreement for many oxygen balanced explosives, but poor agreement for explosives with a large oxygen deficit. For explosives of the ANFO type there is a considerable effect on expansion work by booster size, charge size, and shape.
Recent Work on Deflagration at SMRE
Authors: Murray W. L. , Godwin D. W. , Smith D. T. 
Published: December 2004

AbstractThe paper gives an account of recent work at the Safety in Mines Research Establishment (SMRE) aimed at developing a test of high discrimination for examining the deflagration characteristics of permitted explosives that are designed to be very resistent to deflagration. Experience with an existing apparatus in which an explosive contained in a tube is subjected in the presence of coal dust to the detonation products from a charge of the same explosive is reviewed. More recently experiments have been made using an apparatus of the Audibert‐Delmas type in which an igniter is used to initiate burning in a primer consisting of explosive mixed with coal dust, and the subsequent burning of the adjoining charge of explosive, which may be surrounded by a sheath of coal dust, is followed by measuring the temperature and pressure of the gases in the containing tube. Various possible test arrangements and criteria for assessing the propensity of an explosive to deflagrate are discussed.
Role of Additives in Combustion Waves and effect on stable combustion limit of double‐base propellants
Authors: Kubota N. 
Published: December 2004

AbstractThe effect of additives on the flame structures and the burning rates of double‐base propellants have been examined by means of photographic observations and temperature profile measurements. The additives used for this study are lead salicylate (PbSa, 2%), nickel (Ni, 1%), ammonium perchlorate (AP, 30%), and cyclotetramethylene tetranitramine (HMX, 30%). The addition of PbSa increases the burning rate, but does not improve the flame temperature characteristics. The addition of Ni increases the flame temperature significantly at pressures below 30 atm. The Ni acts as a catalyst to promote the flame reaction while it does not act as a burning rate modifier. The additions of AP and HMX increase the thermal performance of the propellant system, however, the HMX does not improve the stable combustion limit of the rocket motor at low pressures. The addition of Ni or AP is found to increase the flame temperature at pressures below 30 atm, and the stable combustion limit is lowered to below 3 atm.
Relation entre la Structure Electronique et la Sensibilité au Choc des Explosifs Secondaires Nitrés‐Critère Moléculaire de Sensibilité. I. Cas des Nitroaromatiques et des Nitramines
Authors: Delpuech A. , Cherville J. 
Published: December 2004

AbstractRésuméCet article est le premier d'une série où l'on tente d'établir une relation entre la sensibilité au choc des explosifs secondaires nitrés et leur structure électronique. On y met en évidence, dans le cas des nitroaromatiques et des nitramines, le rǒle privilégié lors de la génération de la détonation d'une liaison R–NO2 de la molécule. L'examen des modifications subies par la distribution électronique de cette liaison après absorption d'énergie permet de définir un paramètre parfaitement corrélé à l'échelle des sensibilités expérimentales. La validité de ce paramètre en tant que critère de sensibilité accrédite, a posteriori, l'existence avant la détonation d'un état excité.
Predicting High Explosive Detonation Velocities from their composition and structure
Authors: Rothstein L. R. , Petersen R. 
Published: December 2004

AbstractA simple, empirical linear relationship between detonation velocity at theoretical maximum density and a factor, F, that is dependent solely upon chemical composition and structure is postulated for a gamut of ideal explosives. The explosives ranged from nitroaromatics, cyclic and linear nitramines, nitrate esters and nitro‐nitrato aliphatics to zero hydrogen explosives, carbonless explosives and hydrogen rich explosives. Of the 64 explosives evaluated, 95% had calculated detonation velocity values within 5% of experimental and 98% within 7%. Only nitromethan varied grossly (−; 13%) from calculated velocity and the absolute error for all explosives is ±2.3%.
Thermal Decomposition Process of HMX
Authors: Kimura J. , Kubota N. 
Published: December 2004

AbstractThe thermal decomposition of HMX has been investigated using thermoanalytical techniques and infrared spectroscopic study at both above and below its melting point. The weight loss phenomenon that occurs as the temperature is elevated at a constant heating rate has been clearly separated into four elementary processes which are induction period, sublimation, first order solid phase reaction, and highly exothermic liquid phase reaction by plotting them against the logarithm of the heating rate versus the reciprocal temperature. Hydroxymethyl formamide has been shown to be a major product of the liquid phase decomposition, which suggests that the decomposition of HMX in the liquid phase should be initiated by the N‐N bond scission but not by the C‐N bond scission.
The Preparation of Hexanitrobibenzyl from TNT with sodium hypochlorite
Authors: Gilbert E. E. 
Published: December 2004

AbstractA parametric study of the Shipp‐Kaplan procedure shows promise for the use of reduced amounts of cheaper mixed solvent systems, the use of lower quantities of more concentrated hypochlorite, and elimination of the aging period. Use of methanol as the sole reaction solvent at 50°C shows promise; methanol with a hydrophobic cosolvent gave crude HNBB of high purity. Only a slight improvement in yield was obtained; under no conditions did it exceed 82%.
Effect of initial particle size on the DDT of pressed solid explosives
Authors: Price D. , Bernecker R. R. 
Published: December 2004

AbstractThe effect of the initial particle size on the deflagration to detonation transition (DDT) of pressed, confined explosives has been studied. The explosives examined were ground tetryl, RDX, picric acid, waxed RDX, and waxed HMX. The ground tetryl was studied over the range of 61%−90% theoretical maximum density (TMD); most of the rest of the comparisons were made at 70% TMD. It was found that the initial particle size (or particle size distribution) δ affected the predetonation column length ℓ, the relative time to detonation, and even the apparent mechanism of DDT. Available data in the literature in conjunction with the present results indicate that the curves ℓ versus %TMD at constant δ, and ℓ versus δ at constant %TMD both exhibit a minimum.
Electrothermal analysis as a tool for Designing Electric Detonator Firing Circuits
Authors: Austing J. L. , Tulis A. J. , Schmitt H. R. , Urbanski E. , Mosora J. A. , Hawley J. 
Published: December 2004

AbstractThe use of modified forms of the Rosenthal electrothermal equation to aid in the design of a capacitor discharge firing circuit for a specific detonator is described. The electrothermal parameters Cp and γ, representing the heat capacity of the bridge and the heat loss factor, respectively, were calculated from previously obtained firing data for the detonator. These calculations provided input to the design of a firing circuit utilizing electrolytic capacitors, which have a large value of electrical capacity but also a non‐negligible internal resistance. Calculations were performed which (1) revealed the degrading effect on detonator initiation caused by too large a value of internal resistance, and (2) permitted selection of a particular capacitor that would allow reliable functioning of the detonator with initiation times of about 230 μs. The circuit was designed utilizing this capacitor, and in the experimental evaluation of the circuit the measured initiation times were compared with the calculated values. Good agreement between the two was documented, and the conclusion was reached that the detonator functioned reliably. The merits of the electrothermal analysis and the assumptions utilized therein relative to a vigorous heat transfer/reaction kinetics modeling of the flow of energy from the bridge into the explosive flash charge are discussed in detail.
Experiments of Initiation of Covered, but Unconfined High Explosive Charges by means of shaped charge jets
Authors: Held M. 
Published: December 2004

AbstractExperiments on the initiation of high explosive charges in contact with a barrier or separated from it by a 15 mm air gap or a 2 mm acrylic glass layer have been performed utilising a simultaneous framing and streak camera. With increasing barrier thickness the shaped charge jet is increasingly consumed.
Materials Science and Environmental Qualification applied on solid chemical energetics
Authors: Geißler A. , Schmitt D. , Ziegahn K.‐F. 
Published: December 2004

AbstractIn the environmental qualification of chemical energetics, influences from the environment occurring in production, logistics and applications are simulated. The attempt was thus made to demonstrate or, respectively, to estimate the manipulation safety, functional behaviour and life time of energetic materials. It is here the usual method to intensify simulated environmental influences for the purpose of accelerating tests. In this paper the example of mechanical load simulation is used to demonstrate how knowledge of the behaviour of the material is necessary for an ingenious modelling and a rational increasing of test levels. Apart from the microscopic and macroscopic point of view, especially the so called “micromorphological” observation level is well suited to this purpose.
Strain Distribution in the Uniaxial Tensile Test up to High Strain Rates
Authors: Eisereich N. , Fabry C. , Fischer R. , Geißler A. , Kugler H. P. , Sinn F. 
Published: December 2004

AbstractIn the uniaxial tensile test forces, longitutional and transversal elongation must be measured simultaneously. Recently(1) we presented a non intrusive method to measure both elongations in one experiment. To get more information about the material behaviour beyond the yield stress we modified this test equipment. Now we obtain the strain distribution along the whole sample.
Fick's First Law Correction by an exact solution of the boltzmann equation
Authors: Straub D. , Graue R. , Heitmeir F. , Nebendahl P. , Wurst Th. K. 
Published: December 2004

AbstractIt is shown that there exists a dominant solution of the Boltzmann equation for an artificial model gas in terms of a relation for the diffusion flux differing from the regular formulation of Fick's first law. Its mathematical structure corresponds to the Cattaneo‐formulation based on heuristics of the Fourier heat flux vector. This dominant solution allows a realistic estimation of a diffusion relaxation time and serves as the basis for valuable information concerning two actual problems of hypersonic gas dynamics: first, a useful relation for the calculation of collision integrals for diffusion coefficients, especially at high temperatures; second, a new type of a chemical reaction equation, which is particularly relevant in very fast relaxation processes encountered in the chemistry of fuels.
Organic Fillers for Smokeless Insulations of Double‐Base Propellants
Authors: Pröbster M. 
Published: December 2004

AbstractThe number of organic fillers for smokeless polyurethan‐insulations hitherto known is rather small. In this paper two general formulae, expanding the range of organic fillers, are described. The first formula describes molecules with linear structures, the second one those with cyclic structures. A common feature of the fillers mentioned above their high (N + O)/C ratio.
Ignition Time Delay of polyacrylic fuels‐ammonium perchlorate condensed mixtures
Authors: Girdhar H. L. , Peerzada G. M. 
Published: December 2004

AbstractIgnition time delay of condensed mixtures containing various polyacrylic fuels and NH4ClO4 were measured using hot‐plate technique at several temperatures. The adiabatic theory of explosion assuming condensed phase exothermic reactions was used to evaluate the activation energy of ignition. Activation energy of ignition has been found to be dependent on the decomposition characteristic of the fuel component.
Design and Performance Evaluation of Flat Cone Charge
Authors: Roy P. K. , Rao K. Rama 
Published: December 2004

AbstractThe performance of flat cone charge cannot be calculated by the well known hydrodynamic equations used for conventional hollow charges. As such, experimental studies have been carried out to evaluate the effects of liner cone angle, liner thickness, explosive charge to liner mass ratio and stand‐off on the penetration performance. Generalized equations are established relating the basic parameters with the performance of flat cone charge. A simplified computerized design approach has been suggested which would be useful to the practical weapon designers.
Combustion mechanism of HMX
Authors: Kubota Naminosuke , Sakamoto Satoshi 
Published: December 2004

AbstractThe combustion wave structure and thermal decomposition process of HMX were examined in order to elucidate the burning rate characteristics of HMX. The combustion wave can be divided into three zones: nonreactive solid‐phase, surface reaction, and gas‐phase reaction zones. Measurements with micro‐thermocouples revealed that the heat flux produced in the surface reaction zone is approximately equal to the heat flux transferred back from the gas phase to the burning surface. Accordingly, the reaction process in the suface reaction and the gas phase zones plays a dominant role in the burning rate of HMX. The gas phase reaction zone consists of a two‐stage reaction process: the first stage is the exothermic rapid reaction process between NO2 and aldchydes, and the second stage is the exothermic slow reaction process between NO and N2O and remaining fuel species. The luminous flame zone which is determined to be the second stage reaction process approaches rapidly the burning surface as pressure increases. However, the luminous flame reaction appears to be little responsible for the burning rate of HMX.Examinations of the quenched burning surface of HMX samples revealed that the burning surface melts and forms a noncrystallized intermediate material. The surface structure appears to be different from the structure of thermally degraded HMX samples which were obtained by a thermogravnmetric analysis.
Studies on Thermal Decomposition of Energetic Nitrourea Salts
Authors: Heming Xiao , Jinhua Yuan , Xinquan Xin , Anbang Dai 
Published: December 2004

AbstractThermal decomposition of nitrourea salts (K, Na, Ag, Ba) was studied in hydrogen atmosphere, helium atmosphere and vacuum by gas chromatography and mass spectrometry. The evolution of dinitrogen oxide, water, hydrazine, nitrogen dioxide and the formation of cyanate salts during thermodecomposition of nitrourea salts in helium and hydrogen were confirmed. In vacuum the evolved gaseous products changed to dinitrogen oxide, water, nitrogen monoxide, nitrogen gas indicating that interreaction between evolved gaseous products occurred. The same solid products – cyanate salts – are formed showing vacuum having no effects upon the decomposition mechanism.
Explosive‐Binder Adhesion and Dewetting in nitramine‐filled energetic materials
Authors: Bellerby J. M. , Kiriratnikom Ch. 
Published: December 2004

AbstractThe problems associated with poor explosive‐binder adhesion in nitramine‐filled energetic materials are reviewed. The phenomenon of dewetting and its consequences are discussed and a survey of the literature relating to specific adhesion promoters for RDX‐filled systems is presented.
Manometric Stability Tests of Double‐Base Propellants in vacuum, air, and oxygen
Authors: Havránková E. , Pilná B. 
Published: December 2004

AbstractThe decomposition process of several types of double‐base propellants before and after artificial aging at 75 °C for 20 days was measured in vacuum, air, and oxygen. The results are confronted with those of the test at 100 °C and with the stabilizer content before and after aging. Effects of the sample surface area were also considered.
Calorimetric determination of the heat and products of detonation of an Unusual CHNOFS Explosive
Authors: Ornellas D. L. 
Published: December 2004

AbstractThe heat of detonation of an explosive is determined by its chemical structure and the nature of the products that are formed during detonation. Most explosives contain the elements CHNO and, because plastic bonded explosives often include stable halocarbon polymers, the elements fluorine and/or chlorine may also be present. However, little is known about the effect of the combination of fluorine and sulfur on heat of detonation, specifically the SF5 group. Detonation calorimetry was the experimental technique used to determine the heat and very unusual products of detonation of tris‐(fluorodinitroethyl) pentafluorothio ethylorthocarbonate.
Propellant Gas Phase Chemical Kinetics
Authors: Sheshadri T. S. , Jain V. K. 
Published: December 2004

AbstractAn adiabatic constant pressure chemical kinetic study of the AP gas phase is conducted. The objective is to examine the importance of chemical kinetic studies for propellant deflagration modelling in general and for AP in particular. A reaction mechanism consisting of ninety five elementary reactions involving twenty one chemical species is developed to represent the AP gas phase. An important parameter that can be obtained from the kinetics is the time rate of change of temperature of the gas phase at the condensed phase‐gas phase boundary (dT/dt at t = 0). This is directly related to the heat feedback from the gas phase to the condensed phase. Comparison with earlier work indicates that the use of a one‐step overall reaction could lead to underestimates of heat feedback from the gas phase by a factor of about four. In addition it is found that the rate of decrease of dT/dt at t = 0, with pressure is much larger at lower pressures, suggesting a possible gas phase role in the low pressure deflagration limit. Further, the kinetic study does not support the conclusion of a constant fraction of AP reacting in the condensed phase in the pressure range 20–100 atmospheres. These results are at variance with what is obtained by use of a one‐step overall reaction. Thus, the one‐step overall reaction cannot represent even qualitatively several gas phase characteristics important for deflagration studies, and its use leads to erroneous results. It is concluded that a full reaction mechanism representation of gas phase chemical kinetics is essential to AP deflagration modelling. The same conclusion is probably valid for propellant deflagration modelling in general.
Inhibition Reaction of SrCO3 on the burning rate of ammonium perchlorate propellants
Authors: Miyata Kohsei , Kubota Naminosuke 
Published: December 2004

AbstractThe buring rate of ammonium perchlorate (AP) composite propellants is decreased significantly by the addition of SrCO3 without increasing the pressure exponent of burning rate. Results of microthermocouple measurements indicate that the burning surface temperature is increased from 700 K to 970 K by the addition of SrCO3, although the heat release rate in the gas phase is remained unchanged. DTA (differential thermal analysis) and TG (thermogravimetry) experiments were also carried out in order to determine the role of SrCO3 in the decomposition process of AP. The AP decomposition temperature is increased from 590 K to 620 K by the addition of SrCO3. The results of analysis show that the reduction of the burning rate is caused by the increased AP decomposition temperature.
Carbon resistor gauges for measuring shock and detonation pressures. II. Detonation pressure of carbohydrate‐metal composite explosives
Authors: Tulis Allen J. , Austing James L. , Baker Douglas E. , Hrdina Donald J. 
Published: December 2004

AbstractAn estimate of the detonation pressure of carbohydrate‐metal composite explosives has been obtained experimentally by use of carbon resistor pressure gauges mounted in the wall of the confining tubes. The composite explosives were formulated from a pharmaceutical mixture of 10/90 nitroglyccrin/ß‐lactose by weight, and was rendered detonable by inclusion of flaked aluminum and both flaked aluminum and ammonium perchlorate. The detonation pressure of the nitroglyccrin/ß‐lactose mixture with 10 percent aluminum by weight was approximatcly 1.1 GPa. The incorporation of 30 percent ball‐milled ammonium perchlorate to this formnlation increased the detonation pressure to 12.2 GPa. These pressures must be considered as estimates of the true detonation pressure, because of (a) the suspected non‐ideality of the detonation state of these explosives, (b) the statistical nature of the response of the gauges, and (c) possible inconsistencies in the interpreatation of the gauge records. It is recommended that a number of gauges be used in a given experiment, and the results be averaged as one means of cireumventing the above difficulties.